1. Chemistry

    An element has three stable isotopes. One has a mass number of 63 and an abundance of 50%. The second has a mass number of 65 and an abundance of 30%. The third has a mass number of 67 and an abundance of 20%. Calculate the relative atomic mass of this

    asked by Robert on September 24, 2016
  2. Maths

    Please help. I completed 1-6 but these 4 are hard; the wording confusing. 1) Jane is playing a game of Monopoly, if she throws six on her next turn she will land on community chest. If she throws eight she will land on Mayfair with a hotel (owned by

    asked by Barry on June 29, 2017
  3. math

    Terry bought some gum and candy. The number of packages of chewing gum was one more than the number of mints. The number of mints was three times the number of candy bars. If gum was 6 cents a package, mints were 3 cents each, and candy bars were 10 cents

    asked by john on January 2, 2018
  4. math

    Terry bought some gum and candy. The number of packages of chewing gum was one more than the number of mints. The number of mints was three times the number of candy bars. If gum was 6 cents a package, mints were 3 cents each, and candy bars were 10 cents

    asked by john on December 25, 2017
  5. Science need help

    What is the independent variable? 1 is that the correct answer help plz Sue is setting up an experiment to test whether fly maggots select a dark or a brightly lit environment. She sets up a chamber in which there is a gradient in light intensity from one

    asked by john on December 11, 2013
  6. math

    A pair of dice is rolled, and a number that appears uppermost on each die is observed, Refer to this experiment and find the probability of the given event. (Enter your answer as a fraction)The sume of the numbers ia an add number.

    asked by Maria on April 21, 2012
  7. PSY 369

    Studies have shown that in large American cities, there is a relationship between the number of violent crimes and the number of stores that sell pornography depicting violence. Is this a positive or negative correlation? Provide an explanation.

    asked by Jay on June 15, 2013
  8. Math

    what is 0.000750 in scientific notation? a.75 x 10^-4 b. 7.5 x 10^-3 c.7.5 x 10^-4 d. 7.5 x 10^-5 what is 27/6 written as a decimal? a 4.2 b 4.3 c 4.4 d 4.5 what is 8.57 x 10^-4 in standard form? a.85000 b. 0.00857 c. 8570000 d. 0.000857 which of the

    asked by Sandra on October 17, 2018
  9. math

    The t-shirts for the fundraiser will cost $4.00 to make and there is a $25.00 delivery fee. There are two sized wristbands; a large one that will cost $5.00 to make, and a small one that will cost $3.00. 1. Write an expression to represent the student

    asked by anonymous on June 2, 2014
  10. CHEMISTRY

    what is the symbol for chromium (II) sulfate? You mean the formula? CrSO4 yes! thanx!!!!!! do u know how to find the number of molecules or atoms in a mole? The number of atoms in a mole is called Avogadro's number, the value of which is approximately 6.02

    asked by INEEDHELP!!! on December 4, 2006
  11. Algebra HELP

    Can someone please help me with this Algebra problem. The equation y= -1777x + 27,153 can be used to predict the number of y of gun deaths in the U.S. x years after 2000, that is, x=0 corresponds to 2000, x=2 corresponds to 2002, x-6 corresponds to 2006,

    asked by Susan on May 27, 2010
  12. Math

    Can someone please help me with this Algebra problem. The equation y= -1777x + 27,153 can be used to predict the number of y of gun deaths in the U.S. x years after 2000, that is, x=0 corresponds to 2000, x=2 corresponds to 2002, x-6 corresponds to 2006,

    asked by Susan on May 27, 2010
  13. linear optimization

    During a summer session a student enrolls in two courses, psychology for four hours and engineering for three hours. The student wants to use the available time to amass the largest number of grade points (numerical grade multiplied by the number of

    asked by gemicia on December 29, 2013
  14. Math

    5.Jack participated in a 6 day bike marathon of 430 kilometers. He biked 90 kilometers on each of the first 4 days and y kilometers on the fifth day. Which equation can be used to find b, the number of kilometers Jack biked on the sixth day?

    asked by Jerald on June 4, 2013
  15. Math 1

    write an equation that represents the following situation. Let x= the number of adults. Your equatin should start with "1220=" and use x as the only variable.. The number of students attending the fall play was 150 more than the number of adults attending.

    asked by JJ on October 1, 2014
  16. math

    2. What answer represents this number in scientific notation? 0.00000916 a. 916 x 10^-8 b. 9.16 x 10^-6 c. 916 x 10^8 d. 9.16 x 10^6 3. What is this number in standard form? 6.8 x 10^-4 a. 5,750,000,000 b. 575,000,000,000 c. 0.00000000575 d. 0.575000000000

    asked by chase on September 10, 2012
  17. math

    2. What answer represents this number in scientific notation? 0.00000916 a. 916 x 10^-8 b. 9.16 x 10^-6 c. 916 x 10^8 d. 9.16 x 10^6 3. What is this number in standard form? 6.8 x 10^-4 a. 5,750,000,000 b. 575,000,000,000 c. 0.00000000575 d. 0.575000000000

    asked by chase on September 10, 2012
  18. MATH

    The number of students who ride a bike to school is 15 more than the number of students who walk to school. The letter s represents the number of students who walk to school. Which of these shows the number of students who bike to school? A. s – 15 B. 15

    asked by PLEASE HELP ME!!!!!!!!!!!!!!!!!!!!!!!!PLEASE!!!!!! on March 29, 2012
  19. Math

    1. –(10)^–1 (1 point) –1/10*** -1/-1^10 1/10 10 2. 1/c^-5 (1 point) c^5 5c –c^5*** –5/c 3. What is the value of y^-5/x^-3 for x = 2 and y = –4? (1 point) 10/3 128 -1/128 –128*** 4. Is the number written in scientific notation? If not,

    asked by Bethany on April 22, 2016
  20. Urgent math

    population growth model. Can anybody please help me out in trying to solve this problem? It's my homework and I don't seem to understand what I am getting. The count in a culture of bacteria was 400 after 2 hours and 25,600 after 6 hours. (a) What is the

    asked by Lydia on August 3, 2015
  21. 7th grade math (probability)

    I'm posting corrections from yesterday in addition to new ones. Still not sure how to answer #4. 2. Edwin rolls a number cube and then spins a color from a color card (red, yellow, blue, green, white). What is the probability that he will roll an even

    asked by Alexis on May 6, 2015
  22. Maths Please Help

    Alex and Bella play the following game. They first choose a positive integer N, and take turns writing numbers on a blackboard. Alex starts first, and writes the number 1. After that, if the number k is on the board, the next player may write down either

    asked by Mathslover on May 22, 2013
  23. math

    Consider the given statements. 1. Every prime number is odd. 2. There are 8 prime numbers between 10 and 40. 3. There are 11 composite numbers between 0 and 20. 4. The number 4 is the smallest even composite number.

    asked by angela on July 15, 2014
  24. precalc

    #1 For what positive numbers will the cube of a number exceed four times its square? #2 For what positive numbers will the cube of a number be less than the number? thanks

    asked by Rebekah on October 21, 2012
  25. math

    The number of girls in the choir is 4 times the number of boys in the choir. The total number of students in the choir is 60. How many girls are in the choir?

    asked by steve on November 9, 2015
  26. math/ ratio

    there are 45 fruits. 21 are bananas, 15 are pineapples, and the rest are papayas. what is the ratio of the number of bananas to the number of pineapples to the number of papayas?

    asked by charylle on January 5, 2015
  27. Precalc

    #1 For what positive numbers will the cube of a number exceed four times its square? #2 For what positive numbers will the cube of a number be less than the number? thanks

    asked by Rebekah on October 21, 2012
  28. chemistry

    For another picnic, you want to make hamburgers with pickles, again without having any left over. You need to balance the number of packages of buns (which usually contain 8 buns) with the number of packages of hamburger patties (which usually contain 12

    asked by Anonymous on October 1, 2013
  29. Algebra

    Varun takes a certain number of Rotis during lunch but always wasted half a roti. Rosa takes half the number of Rotis as Varun, and always finishes her share .after 20 days, if the number of Rotis that were consumed during lunch by them together is 110

    asked by Purva on March 19, 2017
  30. algebra

    Choose a natural number between 1 and 100, inclusive. What is the probability that the number chosen is not a multiple of 5? (Enter the probability as a fraction.) Thank you it is appreciated.

    asked by Mary Ann on May 27, 2014
  31. math

    Solve each inequality 1. m-75= 3. p+5

    asked by Elizabeth on November 18, 2016
  32. physics

    11. If 238U92 emits successively four alpha particles two beta particles, what will be the atomic number and mass number of the final product.

    asked by paresh Ghosh on February 4, 2016
  33. Math

    Suppose an experiment involves rolling a fair die 720 times. Find the mean of the number of times a number less than 2 is rolled

    asked by Alyseia on September 30, 2014
  34. Algebra

    find a equation for the line containing the given points. Let x represent the number of years after 2000 and y the number of volunteers in millions. x=5.4 millions y=.11.2 million

    asked by sharon on July 15, 2014
  35. college algebra

    The number of motor vehicle deaths in the US was 49,391 in 1988 and 46,300 in 1990. If the trend stays the same, what will be the number of deaths in 2005? Thank you for any help!!!

    asked by jenny on October 14, 2008
  36. Chemistry

    Calculate the number of moles of CuSO4 contained in 100 ml of 1mole CuSO4 solution. Also find the number of SO4 ~~ ions in it .?

    asked by Awadhesh kumar on June 30, 2015
  37. MATH

    i am thinking of a number. if you multiply it by 7, then add 15, and finally subtract 3^2 you get 48. write and solve an equation that describes the number (x) that i am thinking of. how do i find it? what is x?

    asked by i dont understand! on November 13, 2008
  38. Math

    My home work asks "what is the five number summery of a datta set? How is it used to mAke a box plot?" But i frogot what a five number summery is please help.

    asked by Magiemay on April 25, 2013
  39. math

    mike is playing cars with his sister when he draws a card from a pack of 35 cars number from 1 to 35. what is the probability of drawing number that is divisible by 5?

    asked by Tia on May 27, 2014
  40. 5th grade math

    city council decides to number homes on a new sub divison. However they leave out numbers that are multiples of 3 or 4 and the last home number is 67. How many homes are there on this street?

    asked by tryston on October 5, 2010
  41. chemistry

    In an atom, the maximum number of electrons having the quantum numbers n=5 and §¤ = 3 is: 1. 9. 2. 14. 3. 50. 4. 25. 5. 7. Shouldn't the maximum number be a lot bigger than the answer choices?

    asked by dave on September 14, 2010
  42. Math

    Given a number, a strange calculator can only do the following: multiply it by 2 or by 3, or to raise it to the power 2 or 3. Starting with the number 15, what can be obtained by applying this calculator 5 times consecutively? A) 2^8 . 3^5 . 5^6 B) 2^8 .

    asked by Amitabha on March 14, 2016
  43. Math

    Write 27 as a number is base five. The number 1000^2 is what in base ten? The intersection of two disjoint sets is? Find the solution set of 8x = 32.

    asked by John on January 5, 2011
  44. math

    NUMBER PROBLEMS. You have at least $30 in change in your drawer, consisting of dimes and quarters. Write an inequality that shows the different number of coins in your drawer.

    asked by Anonymous on January 15, 2008
  45. math

    HELP! I have a question , and i need it to be where i can understand it. why is a number, any number, is 1 when raised to the 0 power. i need it for an assessment. and i can't find a site that explains anything to me to where i can understand it enough to

    asked by Yee on January 24, 2018
  46. PRECALCULUS

    write the complex number in standard form a+bi sqrt 7 (cos pi/12 + i sin pi/12) (sqrt = square root, i= imaginary number)

    asked by YOSHI on April 19, 2011
  47. physics

    If 238U92 emits successively four alpha particles two beta particles, what will be the atomic number and mass number of the final product.

    asked by paresh on February 11, 2016
  48. Algebra 1 Honors

    When two numbers are added together, the result is 45. Twice the greater number is six more than five times the lesser number. What are the numbers? 3 months ago Only allowed to use one variable

    asked by Mark Younan on October 30, 2008
  49. 6th grade math

    You roll a number cube 20 times. The number 4 is rolled 8 times. What is the experimental probability of rolling a 4? A. 40% B. 25% C. 20% D. 17% How do I work this problem out? Please explain. Thank you.

    asked by Lily Longoria on May 13, 2016
  50. PRECALCULUS

    write the complex number in standard form a+bi sqrt 7 (cos pi/12 + i sin pi/12) (sqrt = square root, i= imaginary number)

    asked by YOSHI on April 19, 2011
  51. Math

    Having a problem writing an expanded number in notation in descending order. Ex. 92,563,174. I know the placements and the number but have a problem when it comes to write it. Can you please help. I would appreciate an example so much.

    asked by Help Please on May 8, 2013
  52. math

    Estimate 16 20/21*28 3/7 - 4 13/25 + 8 2/47 as a whole number or as a mixed number whee the fractional part is 1/2. a. 452 b.480 c.488 d.492 1/2 I would say the answer is c - 488. Would that be right?

    asked by student on August 24, 2007
  53. Math

    Hello. I need help with this question. A coin is tossed and a number cube is rolled. What is P(heads, a number less than 5 A 1/3 B 5/12 C 2/3 D 5/6 Based on the Info given, i can not figure out the answer to this question.

    asked by Anonymous on June 7, 2014
  54. Math

    The revenue R from selling x number of phone widgets is given by , and the cost C of producing those widgets is given by . Find the number of widget it requires to break even.

    asked by Liz on October 4, 2011
  55. math

    When the product of 6 and the square of a number is increased by 5 times the number, the result is 4. Which equation represents this situation? 6x2 + 5x - 4 = 0 6x2 + 5x + 4 = 0 62x + 5 + x = 4 6 + x2 + 5x = 4

    asked by Doug on May 30, 2017
  56. math

    there are 12inches in 1 foot and 5,280 feet in 1 mile.Explain how you would estimate the number of inches in 1 mile.then find the exact number

    asked by fjoseph on April 2, 2012
  57. Math

    For example 80 71 43 65 45 is the winning number and 51 69 18 81 37 is the machine number,how do i solve this problem to get the accurate next winning numbers from 1-90? Tutor me the exact calculation and formula please.

    asked by Drey on May 18, 2013
  58. Math

    A number cube is marked with 1,2,3,4,5, and 6 on its faces. Suppose you roll the number cube one time. Find the probability of each event. #1. P(4) #2. P(4,5, or 6) #3. P(3 or 5) Could someone let me know if these are correct, THANK YOU! #1. 1:6 1/6 1 to 6

    asked by Plshelp on September 14, 2007
  59. mathsddddddddddddddddddddddddddd

    A composition of the number n is an ordered set of integers a1,a2,…,ak such that a1+a2+⋯+ak=n. The numbers a1,a2,…,ak are called the parts of the composition. Determine the number of compositions of 23 where each part is at least 4.

    asked by shayan on July 18, 2013
  60. math

    If someone had a score of 495/500, What is the mixed number fraction? "I'm confused because if the denominator is bigger than the numerator how can we end up with a mixed number"

    asked by devon on November 14, 2015
  61. pre calc

    Over the course of a year, the number of hours of daylight in Australia is modelled by H=12+3 cos(2pi/365 *t) where t is the time in days and T is the number of daylight.

    asked by jim on January 9, 2012
  62. math

    Use the formula to solve for c. Choose the right answer. Amount Financed (m) = $275 Number of Payments per year (y) = 12 Number of Payments (n) = 18 APR (I) = 12%

    asked by Anonymous on April 20, 2017
  63. math

    The decimal parts of the logarithms of two numbers taken at random are found to 6 decimal places. What is the probability that the second number can be subtracted from the first number without "borrowing" ?

    asked by urgently help needed please on May 2, 2016
  64. English

    Need more aims! 1.activity: after the teacher puts the flascards on the board she writes above each flshcard a number and asks students what is number 2? and so on... aims?

    asked by cary on April 27, 2009
  65. math

    A composition of the number n is an ordered set of integers a1,a2,…,ak such that a1+a2+⋯+ak=n. The numbers a1,a2,…,ak are called the parts of the composition. Determine the number of compositions of 23 where each part is at least 4.

    asked by kk on July 18, 2013
  66. maths

    A composition of the number n is an ordered set of integers a1,a2,…,ak such that a1+a2+⋯+ak=n. The numbers a1,a2,…,ak are called the parts of the composition. Determine the number of compositions of 23 where each part is at least 4.

    asked by kk on July 18, 2013
  67. Chemistry

    I am a bit lost as to how to go about answering this question. Any help will be appreciated. When 1.40g of hydrated magnesium sulphate is heated to constant mass, 0.68g of the anhydrous salt remains. Find the formula for the hydrated magnesium sulphate.

    asked by Nona on March 21, 2007
  68. 7th grade math (probability)

    I'm re-posting corrections originally from Wednesday in addition to new ones. Still not sure how to answer #4. 2. Edwin rolls a number cube and then spins a color from a color card (red, yellow, blue, green, white). What is the probability that he will

    asked by Alexis on May 8, 2015
  69. math

    as well as addition,subtraction,division and multiplication.Sally invents the operation Q. when you see Q between two numbers,you double the sum of their squares. The value of 5Q12 would be ?

    asked by wan on November 10, 2012
  70. Dawn Help please

    Students were asked to write an algebraic expression for the sum of three consecutive natural numbers x + (x + 1) + (x + 2) = 3x + 3. Another wrote (x - 1) + x + (x + 1) = 3x. Explain who is correct and why.

    asked by Math 112 on November 9, 2014
  71. Math/Compound Interest

    Manoj deposited a sum of rs64000 in a post office for 3 years compounded annually 9%/ annum.what amount will he get on maturity?

    asked by muskan on October 12, 2016
  72. Math

    Find the probability for the experiment of tossing a six-sided die twice. Put the answer in a/b form. P(the sum is odd or prime)

    asked by Dana on April 28, 2015
  73. algebra

    Ann is five years older than twice her brother Dan's age, a. Write an algebraic expression to represent the sum od their ages.

    asked by Nicole on October 7, 2010
  74. maths

    x^2+x=12 Since you do not ask a specific question, I assume that you want to find the factors. x^2 + x - 12 = 0 From the above, for the center term, you are looking for two values whose product is -12 and whose sum is +1. (x + 4)(x - 3) = 0 I hope this

    asked by Helen on March 9, 2007
  75. precalculus

    write the expression as a sum or difference of logarithms. express powers as factors show all work log4 sqrt pq/7

    asked by Sara on January 9, 2012
  76. math's

    Manoj deposited a sum of rs64000 in a post office for 3 years compounded annually 9%/ annum.what amount will he get on maturity?

    asked by shubham pandey on October 20, 2017
  77. trig

    It's in sigma notation, so I'm not sure how to type it. I'll just use E lol. Find each sum. 6 E (n+1)/(n+2) n=1 Is this a geometric or arithmetic series? That is pretty much all I really need to know. I appreciate all the help you guys give.

    asked by matt on June 16, 2009
  78. Math

    Find three consecutive integers such that the sum of the first and second is three mose than three times the third. When I did the problem,I got a negative answer. Does that seem correct? Did I make any mistakes?

    asked by Crystal on February 22, 2010
  79. Probability

    Roll four dice one time. What is the probability that the sum will be odd?Can anyone explain/show in detail how to find the answer to this problem?

    asked by Diane on September 12, 2010
  80. pcm

    Find the last three digits of the sum of all positive integers n

    asked by keshav on June 3, 2013
  81. math

    Ann is five years older than twice her brother Dan's age, a. Write an algebraic expression to represent the sum of their ages.

    asked by april on November 9, 2010
  82. Maths

    Mari is 3 times older then nandhini after ten years the sum of thare ages will be 80 find the present age???

    asked by Anonymous on December 4, 2016
  83. math

    Writing in Math To find the sum of 4/9 and 7/12, Mario rewrites the fractions as 8/36 and 21/36. His answer is 29/36. Is Marion right? If not, show his error and correct it.

    asked by LAKSHMI on January 10, 2015
  84. History

    Could someone give be a breif explanation of Canada's 100 days. Everywhere I go there is a long essay thing, could you sum it up for me in a paragraph so I can understand it please.

    asked by Reilly on October 11, 2007
  85. finite math

    After rolling a pair of fair, six-sided dice, what is the probability that the sum of the outcomes is at least 4 but less than 12? (Round your answer to the third decimal place)

    asked by rebecca on March 10, 2015
  86. algebra question

    Find the sum and express in simplest form. (x^2)/(x^2-9)+(2x-15)/(x^2-9) combine the numberator terms: x^2 + 2x -15 which is factorable (x+5)(x-3) Factor the denominator (x+3)(x-3) simplify.

    asked by mike on May 21, 2007
  87. math

    i told some of my classmates about this site and they said it really help but they also added that you all shall show examples when you are finished and an explanation and then give the person a sum similar to that.

    asked by ADRIAN on December 8, 2012
  88. Chemistry

    Please i need sum help in balancing these equations: 1)Phos(p)+Bromine(Br)=phostribromide(PBr) 2)Cacl2+NAHCO3+H2O=Nacl=Ca(OH)2+H2Co3 Thank You

    asked by eva on February 4, 2008
  89. Algebra

    The ages of three brothers are three consecutive even integers. If the sum of the 1st, four times the 2nd, and twice the 3rd is 86, what is the age of the oldest brother?

    asked by Yasmen on August 24, 2013
  90. pre calculus

    A sum of $5000 is be invested in a bank. if the annual interest is 10% and compounded monthly, how long will it take for the original investment to double.

    asked by Raju on February 8, 2014
  91. Math - Calculus

    Question: A box in the shape of a cuboid with a square base is to be made so that the sum of its dimensions (l + b + h) is 20cm. Find its maximum value.

    asked by GZB on July 6, 2018
  92. Calculus II

    Evaluate the integral by first performing long division on the integrated and then writing the proper fraction as a sum of partial fractions. x^4/x^2-9

    asked by Rosali on June 5, 2017
  93. 3rd math

    April needs to estimate the sum of 427 and 338 should she round to the nearest ten or hundred to get the closer answer? Explain.

    asked by morgan on September 20, 2012
  94. algebra 2

    Find the equation that is satisfied by the set of points such that the sum of the distances from the point to (2,0) and (-2,0) is 6. Express your answer in standard form.

    asked by lesly on June 2, 2010
  95. Probability

    Roll four dice one time. What is the probability that the sum will be odd?Can anyone explain/show in detail how to find the answer to this problem?

    asked by Diane on September 12, 2010
  96. Math

    How do I show that the sum of 3 consecutive odd integers is a multiple of 3? Can you please help me answer this question? My teacher didn't explain on how to solve it very well.

    asked by Anonymous on September 18, 2016
  97. Maths

    Jennifer packed some beads into 3 bags labelled A,B,and C.Bag Ahad the most number of beads and Bag C had least.The difference in the number of beads between bag A and the other two bags were 51 and 108 respectively. Given that bag C contained 15% of the

    asked by SRI on February 25, 2014
  98. Physics

    Which of the following is correct for a step-down transformer? Number of turns in the primary coil is less than the number of turns in the secondary coil. Step-down transformer increases the voltage from low value to high value. Number of turns in the

    asked by Liam on October 22, 2012
  99. Grade 11 maths plz help!!!

    A software company started with 2 employees. In 6 months, the company had 7 employees. The number of employees increased in a steady rate. Which equation models the relationship between the number of employees n and the number of months m since the company

    asked by Anjali on September 23, 2008
  100. 8th grade math

    The total number of interior angles in two regular polygons is 17, and the total number of diagonals is 53. How many sides does each polygon have? Show work and explain.

    asked by Anonymous on December 18, 2011