# Critical Thinking/Math

142,111 results, page 75

### Math

A student opened her math book and computed the sum of the numbers on two pages. Then, she turned to the next page and computed the sum of the numbers on those two facing pages. Finally, she computed the product of the two sums, and her calculator displayed the number 62,997. ...

### math

Could someone please check my math questions? any help will be greatly appreciated! 4. Solve: 5|2x + 1 | = 55 Divide both side by 5: |2x+1|=11 2x+1=11 and 2x+1= -1 +1 +1 +1 +1 2x = 12 2x = -10 X=5 x=-6 What my teacher said was wrong~~ 2x+1=11 and 2x+1= -11 YES, for both of ...

### Geometry/Math

Judy lies on the ground 45 feet from her tent. Both the top of the tent and the top of a tall cliff are in her line of sight Her tent is 10 feet tall. About how is the cliff? Assume the two triangles are similar. Postscript: The distance from the tent to the cliff is 400 feet...

### math

Anxious Billy Bob pulled out his math recording sheet and saw the following scores 54,62,65,68,70,70,78,82,84 A. He want to calculate his average.Which measure of center is the average?compute it ? I have this :The measure of center is the average, mean 633/9=70.33=about 70% B...

### english

Please help me to correct grammar Task 3 – Unit review (Summary and critique) According to Brown and Hood’s “Academic Encounters: Life in Society” (2002), Intermediate to High Intermediate Level, includes unit 1: Belonging to a group, consists of chapter 1 and chapter ...

### Psychology

Could someone see if I got any of the questions wrong. I feel that some questions have multiple answers but there is only one that is correct. Please help. thanks a lot Cognitive Development Respond to the following statements using Piaget’s Stages of Cognitive Development 1...

### Decision Making

I am looking for information on (groupthink/devil's advocate). Why I need it. The CEO has been extremely frustrated with what has been occurring within the organization lately. In a recent manager meeting he exclaimed, "Everyone around this place just follows the status quo. ...

[History Homework] Please answer 1. What are 2 pieces of technology essential today? 2. If you could give a prehistoric person one item from today what would it be? 3. Why is writing important for civilizations? 4. Why is theater/drama important to society? 5. What are some ...

### math

I asked sue a question yesterday and don't understand the answer can you explain? Here what it was I think this question has a typo because none of the multiple choice answers fit. The question is which of the following values is in the solution set of inequality 8-7x<-6? A...

### Writing

How can I write my research paper to where my research makes sense? The first thing you have to do is come up with a point. I saw you were asking a lot of questions about the holocaust (I assume this is the same Brooke), so assume this is what you're writing on? What, exactly...

### Math

Hi Sorry I'm reposting this question, I think the answer that was provided was not correct because of the ambiguity of the original question but if I could have someone workout the question as written it would be much appreciated: See below discussion. 4x^3y^-2 / 2x^-1y^4 is ...

### Heeeeeeeelp

Read the following instructions in order to complete this assignment and review the example of how to complete the math required for this assignment: Use the properties of real numbers to simplify the following expressions: 2a(a – 5) + 4(a – 5) 2w – 3 + 3(w – 4) – 5(...

### math

The average of 5 numbers is 28. What would the 6th number have to be to bring the average up to 30? Anne’s average in math is 92. She wants to raise her average to 93 so she will make an A. she is taking a test on Friday. What score will she have to make on the test to raise...

I have a question on math if I start to look for a object hidden by making the center of a field as (0,0), with coordinates giving distances in yards. Coordinates to the north or east are positive and coordinates to the south or west are negative. And I find nothing at (-12,8...

### math

An advertisement states that eight thermometers cost \$12.42 minus a 3% discount. Dr. wants to order a dozen to take advantage of the savings, sales tax is 5%. What would the cost be? Is my math right? I divided 8 by \$12.42 and got \$1.55 p/thermometer. 12*\$1.55 would cost \$18....

In the fall of 2000, 54% of the almost 34,000 first-year students attending one of the California State Universities had strong enough math skills to take an entry level course. 1)Based on a sample of 20 students, can we assume our calculations will be accurate? My answer is: ...

### math

(1 point) Calculate the mean and median of the following grades on a math test: 97, 88, 89, 86, 83, 80, 78, 74, 64, 62, 49 Mean = Median = Is this data set skewed to the right, symmetric, or skewed to the left? (Enter "SKEWED RIGHT", "SYMMETRIC", or "SKEWED LEFT");

### Critical Thinking

Hello, Im new here and im having problems with my homework. I need to do these two things for different sources and i find it next to IMPOSSIBLE to find these... Identify and name any rhetorical devices used by the author. If none exist, explain how you determined this. ...

### math,help

can someone help me with this i am lost now i've been doing math for the past 8 hrs. Problem # 1 solve: 4(x-10)-3x=x-40 Problem # 2 solve for t: a = p + prt Problem#3 translate to an algebraic equation 7 less than the quotient of a number and 3 is twice the same number problem...

### Math 7 - NYS Math Exam Review - Book 1 (HW)

C = 2nr!?!??!??! Since the NYS Math Exam is coming up (in my district in my school we have it next week). You see in my class were not done with our geometry and ratio, proportion unit and plus we are missing one unit: algebra. We didn't get to solving the formulas. Ratio and ...

### Math

Each day Julia's math Teacher gives class a warm up qs. It's true/false 20% of the times and multiple choice 80% . Julia gets 70% on true false correct and 90% on multiple choice correct. Julia answered today's question correctly. What's the probability that it was a multiple ...

### Math

Please help me with this math problem. A woman is given a loan of \$20,000. for 1 year. If the instrest charged is \$800, the was was the intrest rate on the loan? To get the answer I set the problem up like this: R= 800/20,000= 25(1/100)= 25/100= 25% but I know this cant be ...

### Entrepreneurship

You just received an email from your high school friend, Bill Hudson. You went to college, and then business school, while Bill stayed in your home town. Despite the differences in your paths, you are still very good friends. Bill is considering a life-changing opportunity and...

### Math

I have a math sheet for homework and most questions are similar to the following: Bob is making treat bags for his daughter's birthday party. he decided to use the recipe below for each bag. 1/3 cup peanuts 3/4 cup pretzels 1/5 cup raisins 2/3 cup popcorn He needs to make to ...

### math 115

1. sabrina has the following math quiz scores. 19, 24, 25, 17, 13, & 18. find her mean score, to the nearest tenth if necessary.= 13 is this correct? 2. eleven applications for a certain position had the following ages. 32, 33 ,25, 36, 48, 51, 28, 23, 54, 52, 45. what was the ...

### Physical science

1. Which of the following frequencies falls in the range of RF wavws used by commerical radio broadcasting stations a. .60 HZ b. 6,00 HZ c. 600.00 HZ d. 6,000,000 HZ 2. In a cathrode ray tube, the number of electrons that reach the fluorescent screen is controlled by the a. ...

### math

need help with math word problems. just don't understand. What is the number? you have a four digit number where the thousands digit is four greater than the hundreds digit.The tens digit is twice the thousands digit. The ones digit is half of the thousands digit. What is the ...

### MATH 115

I have math questions I need to check my answers can you please help me 1. 4x4x4x4x4 as a power of 4 answer 4 to the fifth power 2.a bedroom is 10 ft by 11 ft what is the perimeter? answer 42 ft evaluate 72/8-9/3=6 3.Jamal is fencing a rectangular field that measures 25 ft by ...

France is one of the most popular tourist destinations in the world, and I discovered a few of the reasons why so many people visit the country during a recent excursion. While in France, I visited numerous world-famous landmarks such as the Eiffel Tower and the Champs-Élysé...

### science(chem&statistics)

I have to write a abstract for my paper I was wondering if it was better to write it at the beginning or the end of the lab report. If I was to eliminate 1 value as an outlier would I go and include that in calculations of the RSD? I would assume not since It would affect the ...

### Calculus

What is wrong with the following reasoning??? f(x) = 2^x f'(x) = x[2^(x-1)] Although n x^(n-1) is the derivative of x^n, you cannot apply similar rules when x is the exponent and the number being raised to a power is a constant. The derivative of b^x, where b is a constant, is...

### accountig

Continuing Cookie Chronicle 1 Continuing Cookie Chronicle (Note: This is a continuation of the Cookie Chronicle from Chapters 1 through 7.) CCC8 One of Natalie’s friends, Curtis Lesperance, runs a coffee shop where he sells specialty coffees and prepares and sells muffins ...

### MATH

I have 2 questions the first I have narrowed down to 2 possible solutions the second has 3. What is the solution to log sub 5 (2x+3)=2 a)13/2 or b)14? The next problem f(x)= log sub 5 x what is the value of 1/25? a)square root of 2 b)-1/2 or c)1/2? Help is greatly appriciated...

### English

1. Can you help me with this? 1-2. Can you help me do this? (Are both the same?) 2. Can you help me with cleaning the room? 3. Can you help me about cleaning the room? 3-1. can you help me clean the room? 3-3. Can you help me on cleaning the room? (Are they the same? Can we ...

### math

The area of a plot of land is 2496 square meters. A small part of the land is fenced. The ratio of the area of the plot of land to the area that is not fenced is 48:31. What is the area of the land that is not fenced? (5th grade math)

### math exponents

x to the - power x to the fraction power x to the -fraction power how are they different? 2-2=1/22=1/4 21/2= sqrt 2 = 1.414 2-1/2=1/21/2=1/1.414=0.707 math is really gay u no what is the historical facts on exponets

### PHYSICS HELPPPPP

A diver descends from a salvage ship to the ocean floor at a depth of 35 m below the surface. The density of ocean water is 1.025x10^3 kg/m^3. a) Calculate the guage pressure on the diver on the ocean floor. b) Calculate the absolute pressure on the diver on the ocean floor. ...

### math

did you know when you try to find the least commen multiple of 3 numbers you have to divide by two after you get your answer my class (ms.lott in texas) told us that for some reason its doubling the number so always divide by two once you have crossed out the commen numbers ...

### Math

How do you solve a double sided variable? I am not sure what you are asking. Even so, since this is not my area of expertise, I searched Google under the key words "'double sided variable' math" to get this possible source: http://en.wikipedia.org/wiki/Math_24 I hope this ...

### Math

A company is increasing production at the rate of 25 units per day. The daily demand function is determined by the fact that the price (in dollars) is a linear function of q. At a price of \$70, the demand is 0, and 100 items will be demanded at a price of \$60. Find the rate of...

### Math

16.Eliot spent 24 minutes solving 8 math problems.At that rate, how many math problems can he solve in 54 minutes? a.12 B.16 C.18 D.24 A? 17.Ronald got 92% of the problems correct on a test.Which number could also represent 92%? A.9.2 B.0.092 C.9/2 D.46/50 D 18.Lakeshmi made a...

### math

I have a math question for my cell biology class. A molecule exchanges places with its neighbor every 10^-7 seconds. It will diffuse from one end of a 2 micrometer cell to the other in 1second. Ok now I have a 6M x 6M room filled with 4cm ping pong balls. I have to determine ...

### Math - Algebra 2 some1 plz help?

in a certain math class, each student has a text book, every 2 students share a book of tables, every 3 students share a problem book, and every 4 students share a mathematics dictionary. If the total number of books is 75.. how many students are in a class? how many students ...

### Math

On Tuesday, Leslie spent 47 minutes on math homework, 39 minutes on science homework, 52 minutes on English homework, and 44 minutes on history homework. How much time did Leslie spend doing her homework on Tuesday?

### Math

I am a four digit number, I am between 2,000 and 3,000 the digit in the ones place is four times as much as the digit in the thousands place. Only one of the digits are the same. The digit in the tens place is one more than the digit in the hundreds place. All of the digits ...

### English

I had to place these statements in the Fallacy Types I thought they belonged in. Did I do this right or am I completely wrong here? Fallacies are confusing.Thanks Everyone Ad hominem/genetic 7. I don’t care if she is the top psychiatrist in the state! Her theory on sibling ...

### math

How do you rotate an object in a graph?? It depends on what point you are rotating the plot. The math is somewhat advanced, so I don't know your level. i just need to rotate it..like 180 and 90.... Ok, rotating about the origin. For ninety degrees, counter clockwise, the old x...

### math math

Translate to an equation: p \$25 potted plants and s \$20 shrubs total \$300 Graph the equation and use the graph to determine three different combinations of potted plants and shrubs that total \$300

### math

If 8 people went to a party and each person shook hands at least one time. how many total hand shakes would there be? Think about how many people the first person would shake hands with, how many people the second person would shake hands with, and so forth. THANK YOU FOR YOUR...

### math help

could some one please explain to me reciprocal how to find the reciprocal my math home work says find the reciprocal of (-1/8)(13/2)(4) reciprocal you change over so is the -1/8 -8/1 or would it be 8/1 13/2 would be 2/13 4 would be 4/1 then 1/4 then i would multiply all ...

### Math

Abby can buy an 8 pound bag dog of food for \$7.40 or a 4 pound bag of the same dog food for \$5.38. Which is the better buy? My answer: I would have to say to buy an 8 pound bag of dog food. I am confused though if they are asking what math operation to do. Please assist me if ...

### math,mathguru

you asked me about how did i came up with my answer this is what i did: Write each fraction in simplest form. #18 (-5x^3y^3)/(-20xy^4) = (3X(-5)X(x)X(x)X(x)X(y)X(y)X(y))/(2X2X(-5)X(x)X(y)X(y)X(y)X(y)) = after canceling the common terms top and bottom i am left with = 3 and 2 ...

### Math

1.how many different permutations can you make with the letters in the word s e v e n t e e n ? 2.a teacher has a set of 12 probelms to use on a math exam. the teacher makes different versions of the exam by putting 10 questions on each exam. how many different exams can the ...

### Pre algebra

How do I complete each ORDERED PAIR solution to the given equation? y=-x+9;(4),(9),(0) I looked up math ordered pairs at www.google.com, and these are the results. There may be a site in here with an explanation to help you. http://www.google.com/search?q=math+ordered+pairs&...

### Math

I have three math problems that I have tried to solve but I do not think they are correct. Can someone please help me! 1. What is the product of 225 and 507? I came up with 225 x 507 = 114075 2. Divide by moving the decimal point. 10.5 ÷ 100 I came up with 0.105 to be the ...

### English

1. He solved two math questions with ease. 2. He solved two math problems with ease. 3. He solved two mathematical problems/questions with ease. (Are all the same? Which one is commonly used?)

### Math

You have a Spanish club meeting every fourth day and a math club meeting every tenth day. When is the first time they will meet on the same day? My Answer: 4 + 10=14 they would meet on the 14th day Would that be the correct answer? I am confused.

### math

help please find the greatest common factor of 385 and 1365. 385=5x7x11 1365=3x5x7x13 now which factors do you see common? 5x7 or 35 Here is what I had 385=5x7x11 1365=3x5x7x13 5x7=35 is this correct yes, exactly how I showed you thank you yes your math is correct

### Math

Hi. I found this question on a Math Counts practice test and it seriously confused me. I've never learned about this, and it would help if someone helped me. Thanks in advance. How many elements are in the intersection of the set of all the prime numbers less than 30 and the ...

### Math

I need help with these three math question. 1st question. What is the additive inverse of 5 on the 12-hour clock? 2nd question. What is the equivalent number on the 12-hour clock. -22 the choices for this question is, 5 or 2 or 3 or 1. 3rd question. I need to find the additive...

### Math

the average score on a math test for 16 students was 66. six more students took the test. the average of the six was 74. What was the average of all of the students?

### Early Child Ed.

Would you please help with this question? (These questions that asks which is "NOT" really confuse me)!! Which one of the following is usually an effective way to stop disruptive behavior that is NOT harmful to the child or others? A) Remove the child from the group ...

### Math, Science, Writing, Language, Test Preparation

I was wondering can I receive website to help me prepare for vocabulary, geometry, chemistry, PSAT, SAT, and ACT Thanks Study skills are number one, as far as I can see. Subject areas are included in these sites, too: http://www.studygs.net/ http://www.d.umn.edu/kmc/student/...

### Re: Physics/Math

A can of sardines is made to move along an x axis from x1 = 0.2 m to x2 = 1.2 m by a force given by F = iF0exp(-0.4x), with x in meters and F0 = 4.5 N. (Here exp is the exponential function.) How much work is done on the can by the force? For Further Reading * Physics/Math - ...

### Math (Algebra II)

I'm trying to finish up my summer math packet, and I'm almost done, but I'm having trouble figuring out this one: "Divide and simplify these expressions." (3x^4 - 2x^3 + 16x - 192) / (x^2 - 8) so, that's 3x to the 4th, minus 2x cubed, plus 16x, minus 192 ---> all divided by...

The High School Step Team Karla’s cousin Jade urged her to join the step team. “This afternoon you should definitely try out!” Jade suggested after the final bell rang. “I know she wants the best for me,” Karla thought to herself, “but I’m not sure I’d be any ...

### Math

Can you please help me with a math problem Suppose the ball was 3.24 feet above ground when it was hit, and that it reached a maximum height of approximately 102.51 feet when it had traveled a ground distance of approximately 214.26 feet. The ball lands after traveling a ...

Can someone help me figure out the way to solve this math word problem? Gerri bought a small bag of peanuts and ate 1/2 of the peanuts on Monday. On Tuesday, she ate 1/2 of the peanuts that were left. On Wednesday, she ate 1/2 of the peanuts that were left from Tuesday. She ...

### Language Arts

civil Disobedience Part 2: Thoreau’s ideas had a profound effect on a man named Gandhi. Gandhi, was a leader in India who worked to end British rule. He led India to independence and inspired many to non-violent forms of protest and resistance. He fought to end poverty, ...

### Math

math puzzle: i am less than 3000. all four digits are odd. all four digits are different. the sum of my tens digit and ones digit is 16. i am divisible b 13. who am i? Ans: the thousand digit must be 1, the hundreds digit is 3 or 5. The tens and ones digits are 9,7 or 7, 9. So...

### math

Eddie buys 100 sheets of heavyweight paper to make a notebook. He places 1/4 of the sheets in a section for English and 1/3 of the reamining sheets in a section for math. Which section is thicker if the 100 sheets of heavyweight paper is 2/5 in per 100 sheets?

### psychology

# 1.21 (1 pts.) William is acutely retarded and requires intense care. His IQ has been measured at approximately 15. What term would be used to classify William's level of retardation? A) mild B) moderate C) severe D) profound # 1.22 (1 pts.) Shannon has been diagnosed with ...

### Philosophy

I have to write an essay (1000 words) on Niezsche (explain the phrase 'God is dead'). So far I have nearly 600 words. I am struggling with it though now. Here is what I have written: Friedrich Nietzsche was a German philosopher of the 19th century. He wrote many critical texts...

### math

Sally answered 90% of the math test questions and 80% of the history test questions correctly. If each test had 50 questions, how many questions in all did she answer correctly? I think that she answered 85 questions in all that were correct. Am I right?

### Math

This math question i do not get it is Sanjay earns \$13.00 each week from his papaer route.He earns \$.15 for each daily paper and \$.35 for each sunday papaer he delivers. He delivers twice as many daily papers as sunday papers. How many of each type does he deliver each week. ...

### Math

This math question i do not get it is Sanjay earns \$13.00 each week from his papaer route.He earns \$.15 for each daily paper and \$.35 for each sunday papaer he delivers. He delivers twice as many daily papers as sunday papers. How many of each type does he deliver each week. ...

### MATH

IF JACK AND JILL ARE COMPARING RESULTS OF A MATH TEST AND jACK HAD 40 CORRECT ANSWERS AND JILL HAD 50 CORRECT ANS AND THERE WERE 32 QUESTIONS THEY BOTH GOT RIGHT AND 6 THEY BOTH GOT WRONG. HOW DO I FIND THE NUMBER OF QUESTIONS ON THE TEST?

### Math

I'm confused about a question on a math test. The question is: Which statement is a true statement? The answer choices are: A. All rectangles are squares B. All squares are rectangles C. Every rhombus is a rectangle D. Every rectangle is a rhombus. I really need help. Thanks!

### Math

Hello, I need help with a 5th grade math question. The red train returns to central station every 45 min. The blue train returns to central station every 60 min. If both trains leave the station together, in how many min. will they both be back at the station at the same time?

### math plzzzzzzz help

this is grade 10 math questions a rectangular window is 5 feet 3 inches in length, and 3 feet 6 inches in width. if the perimeter of the window must have caulking that costs 32cents per inch, how much will the caulking cost?? the answer is \$67.20 but i got 846.73 :( what i did...

### Science/Math/HElP

Science- A 25N object is 3 meters up. How much potential energy does it have? our teacher said that the formula for finding out potential energy is PE = Mass * Gravity * Height. The gravity on Earth is always 9.8, but my problem is that instead of mass the object is measured ...

### math,correction

Can someone help me with these...plz Simplify 2radical (12) + 4 radical (27) if i simplify radical (12) i get 2radical (3) then if i simplify radical (27) i get 3radical (3). so now i don't know if i'm doing this correctly or how to set it up... 2 sqrt 12 + 4 sqrt 27 4 sqrt 3...

### math

My Math Problem When wrapping a birthday gift for his mother, Kenji adds an additional 2.5 square feet of gift wrap to allow for overlap. How many square feet of gift wrap will Kenji use to wrap a gift 3.5 feet long, 18 inches wide, and 2 feet high? My answer is 30.5 square feet

### history

the Puritan dilemma 1. Englishmen rejoiced when Henry VIII turned his back on the Pope because now they felt they would be free to join the Protestant Reformation and gain a purer church. A) True B) False 2. Puritan's believed that marriage came before God. A) True B) False 3...

### science(chem) Dr.Bob-> need help on this long lab

For 1 part of the lab I: prepare 4-Bromo-2-chloro-6-iodoaniline I dissolve 250mg recrystallized 4- Bromo-2-chloro-6-iodoaniline in 4ml of glacial acetic acid in 25ml erlenmyer flask and add 1ml water to the mixture. Then I prepare a solution of 250mg technical iodine ...

### math

*The value of the z-score in a hypothesis test is influenced by a variety of factors. Assuming that all other variables are held constant, explain how the value of z is influenced by each of the following: a. Increasing the difference between the sample mean and the original ...

### Chemistry

1/[N2O] = 1/(1.75M) + (1.10E-3M^-1 S^-1)(1852s) [N2O] = 0.383 M I know I posted a similar question but I am having trouble with this one as well. Should I do 1/1.75 first and then add 1.10e-3 and then multiply by 1852? Math(Thank you for your help) - john, Friday, March 9, ...

### Math

There is a football field and the length shows 120 yd and the width is 53 1/3 yd a. What are the dimensions of a football field in feet? b. A chalk line is placed around the perimeter of the football field. What is the length of this line in feet? c. About how many laps around...

### math

\$340,000 in budget for 210 employees inyr 1988, in1989 there were 267 employees with same budget. What should've been budget for 1989 and what was % of change from 1988 to 1989? Show me the formula for the answer Nicole: The way this works is that you do as much of a problem ...

### math

1.solve for the given variable: x + 1/2 = 1 1/2 3/4 1*** 2 3 2. solve for the given variable: 10/13n = -30/39 -20/13 0 100/169 -1*** 3. solve for the given variable: k-3/4 = 10 43 5.5*** 37 52 PLEASE HELP ME WITH MY MATH!!!!

### Math

Diane took a math test. The ratio of the number of problems Diane got incorrect to the number of problems she got correct was 2:7. If the test had 36 questions on it, how many problems did she get correct?

### Math Word Problem

Please help with this math word problem: Jamal has a 5X7 picture that he took on his summer vaction and he wants to use a photo copier to enlarge it to an 8X10 picture. To enlarge Jamal has to specify a percent between 50% and 200% on the copier. Explain 2 different ways Jamal...

### Math

Name School Team Event 3: Logic and Reasoning (with calculators) 5th/6th grade Math Meet ‘08 For each number pattern, fill in the next five terms. (2 pts. each blank) ANSWER KEY 1st term 2nd term 3rd term 4th term 5th term 6th term 7th term 8th term 9th term 10th term 1) 2) ...

### Math

Hello I did my math homework, but I need someone to check if I did it right or not. 1. A = z>=4 B = z<7 Write A or B and A and B using interval notation Answer: A or B = (-infinity, infinity) A and B = [4,7) 2. Write the algebraic expression for the following: 8 is less ...

### Math

A math class has girls and boys in the seventh grade and girls and boys in the eighth grade. The teacher randomly selects a seventh grader and an eighth grader from the class for a competition. What is the probability that the students she selects are both girls? Write your ...

### math

Hi I am looking for a certain number line for a test you guys should have a place in search so we all can show you if you have it then this web site will be poppen well i had a math qestion to it goes like this i had 55 apples and i got 100 more then i gave 44 away then I ...

### Chemistry -thanks

Hi,there was an error with the procedure. 1.0g NaOH sample was dissolved in 5ml of water and acidified with 4ml of conc. nitric acid,not dilute nitric acid. This was then made up to 15ml with water.After acidifying with conc. nitric acid instead of dilute nitric acid, no such ...