Saturday

February 25, 2017
Total # Posts: 721

**Math**

A school is holding a Fixed Raffle, where only a certain number of raffle tickets can be sold. The school sold 970 of these tickets for $10 each. One of the tickets will win $2910, two tickets will win $970, and 5 tickets will win $485. What is the expected ...

*February 23, 2017*

**MAth**

Darth Vader is designing a game that costs $20. The game consists of pulling a colored rock out of a container. When the rock is Red Darth Vader pays nothing, when the rock is Blue Darth Vader pays $40, and when the rock is White Darth Vader pays $100. The first ...

*February 23, 2017*

**MAth**

The odds against Rainbow winning the race are 17:5. Brian bets $120 on Rainbow to win and Rainbow does win the race. How much money does Brian win? What was the probability that Rainbow was going to win the race?

*February 23, 2017*

**Maths**

$12 000 is invested at 6% p.a. for 42 months. How much interest is earned each year and how much interest is earned after 2 years?

*February 21, 2017*

**chem**

What are the molality and mole fraction of solute in a 25.5 percent by mass aqueous solution of formic acid (HCOOH)? work this one out please i didnt understand

*February 19, 2017*

**chemistry**

What is the molality of a solution containing 11.1 g Na2SO4 dissolved in 2269.2 g of water? Just making sure would it be 11.1 divided by 2269.2 times 100?

*February 19, 2017*

**Chemistry-Urgent**

okay thanks so much dr. bob you're literally the reason i just passed my chemistry homework :)

*February 19, 2017*

**Chemistry-Urgent**

molality or mole fraction?

*February 19, 2017*

**Chemistry-Urgent**

for which one?

*February 19, 2017*

**Chemistry-Urgent**

thanks drbob222

*February 19, 2017*

**Chemistry-Urgent**

okay now last question..i didnt understand how you did this one (What are the molality and mole fraction of solute in a 25.5 percent by mass aqueous solution of formic acid (HCOOH)?

*February 19, 2017*

**Chemistry-Urgent**

im not actually suure im just not the best at chemistry and was very confused

*February 19, 2017*

**Chemistry-Urgent**

.0345

*February 19, 2017*

**Chemistry-Urgent**

oh .07817

*February 19, 2017*

**Chemistry-Urgent**

isnt that 1?

*February 19, 2017*

**Chemistry-Urgent**

oh 142.04

*February 19, 2017*

**Chemistry-Urgent**

is that .44068?

*February 19, 2017*

**Chemistry-Urgent**

so 1 divided by 2.2692

*February 19, 2017*

**Chemistry-Urgent**

so it would be 11.1 divided by 2269.2 times 100?

*February 19, 2017*

**Chemistry-Urgent**

What is the molality of a solution containing 11.1 g Na2SO4 dissolved in 2269.2 g of water?

*February 19, 2017*

**Chemistry-Urgent**

The partial pressure of CO2 inside a bottle of soft drink is 4.0 atm at 25°C. The solubility of CO2 is 0.12 mol/L. When the bottle is opened, the partial pressure drops to 3.0 ? 10-4 atm. What is the solubility of CO2 in the open drink? Express your answer in grams per ...

*February 19, 2017*

**Chemistry-Urgent**

What is the percent by volume of ethanol in a solution that contains 26 mL of ethanol dissolved in 113 mL of water? explain please

*February 19, 2017*

**Chemistry**

Thanks dr bob. can you help me with the rest

*February 19, 2017*

**Chemistry**

You have 1683.8 g of a bleach solution. The percent by mass of the solute sodium hypochlorite, NaOCl, is 3.62%. How many grams of NaOCl are in the solution? (show work Please)

*February 19, 2017*

**Chemistry**

DRboB im confused on how you worked this one

*February 19, 2017*

**Chemistry**

What are the molality and mole fraction of solute in a 25.5 percent by mass aqueous solution of formic acid (HCOOH)? (Explain how you got the answer please)

*February 19, 2017*

**Solstudies**

What is Williamsburg originally named

*December 11, 2016*

**Math**

What is the definition for composite

*December 11, 2016*

**Math**

What is the definition for composite

*December 8, 2016*

**Language Arts**

15. Read the following lines from the story “Forbidden Fruit.” Of course, in childhood there were occasions when I could have tasted pork in kindergarten or ate at the home of a friend, but I never broke the commandment. When we had rice and pork in kindergarten, I ...

*December 6, 2016*

**Language Arts**

Read the following passage. Then answer the questions that follow. THE OLYMPIC SWIMMER Who will be the winner bold? Athletes from both far and near Train and Strain to be the best. But who will win the medal gold? Swimmers swivel, splash, and kick Back and forth in a clear, ...

*December 5, 2016*

**Language Arts**

OK, thanks!

*December 5, 2016*

**American Government**

Has anyone done the Memo to the president portfolio? I am like...really stuck on it.

*December 1, 2016*

**Math**

14 bottles of water costs $56.How much would you pay for 50 such bottles?

*November 28, 2016*

**history**

wat year was abraham lincoln great great grandma born in.

*November 1, 2016*

**Algebra**

(3-2i)^2

*September 27, 2016*

**Math**

What is the distance, to the nearest tenth, from S(4,-1) to W(-2,3)

*September 13, 2016*

**math**

these are the options: One inch represented 1 foot in the first scale, but now 1 inch represents 4 feet in the second scale. One inch represented 4 feet in the first scale, but now 1 inch represents 3 feet in the second scale. One inch represented 54 feet in the first scale, ...

*September 7, 2016*

**math**

Rihanna planned a rectangular courtyard for a park and made a scale drawing using inches as the unit of measurement. She originally planned for the length of the actual courtyard to be 54 feet, but she decided to change it to 72 feet. If the length of the courtyard is 18 ...

*September 7, 2016*

**math**

40 = 25 + 15 and all multiples to it

*September 7, 2016*

**Chemistry**

Calculate the volume of 1.0 M CuSO4 stock solution you should use to make 100 mL of a 0.010 m CuSO4 solution.

*September 1, 2016*

**Math**

17degrees

*August 11, 2016*

**Math**

8th Grade Math 180degrees - (125degrees+38 degrees) = x degrees how do i solve this ?

*August 11, 2016*

**Algebra**

The variable Z is directly proportional to X. When X is 6, Z has the value 72. What is the value of Z when X = 13

*July 24, 2016*

**Math**

Marge bought a computer for $699 on the installment plan. The terms of the plan were a down payment of $100, then payments of $58 a month for 12 months. How much was her total cost?

*June 15, 2016*

**Sxiences**

A force of 200 N causes an object to accelerate at 2m/s^2. What is the object's mass?

*June 1, 2016*

**Functions**

A car has 16 gallons of gasoline in its tank when it starts it's journey. On a long highway trip, gasoline is used at a rate of about 2 gallons per hour. The gallons of gas, "g", remaining in the car’s tank after "t" hours can be modeled by the ...

*May 12, 2016*

**Functions**

You own two restaurants. From 1995 to 2000, the sales R1 (in thousands of dollars) for one restaurant can be modeled by: R1 = 480 – 8t – 0.8t2, t = 0, 1, 2, 3, 4, 5, where t = 0 represents 1995. During the same 6-year period, the sales R2 (in thousands of dollars) ...

*May 12, 2016*

**Functions**

You purchased a new car for $22,000. The value of the car decreases by 15% each year. Which function could be used to model the value of the car, "V", after "t" years?

*May 12, 2016*

**Algebra**

Simplify x/6x-x^2 A. 1/6-x; where x = 0,6** B. 1/6-x where x= 6 C. 1/6x where x=0 D. 1/6 Simplify 5x^3/7x^3+x^4 A. 5/7+x; where x = 0,-7 B. 5/7+x; where x=-7** C. 5/7x; where x = 0 D. 5/7

*April 28, 2016*

**Calculus I**

The volume of a sphere is changing at a rate of 8pi cm/sec. What is the rate of change of its surface area when the radius is 1? (the volume of a sphere is given by V=4/3pir^3 and its surface area, by A=4pi r ^2).

*April 12, 2016*

**Physics**

What is common to all light sources, including incandescent, fluorescent, neon, halogen, laser, and sodium vapor devices?

*April 11, 2016*

**Consumer math Help please**

You (or your parents) purchase a new car for $16,725.00 plus 6.15% sales tax. The down payment is $1,400.00 and you (or your parents) have an average credit rating. How much interest is accrued after the first month? Average Credit score APR (%)- Secured =5.85% Unsecured= 6.20%

*April 8, 2016*

**English**

Please help!

*April 5, 2016*

**English**

Which of the following quotes spoken by Juliet shows the strongest example of how she changes over the course of Romeo and Juliet? A. Madam I am here what is your will B. I'll look to like if looking liking move: but no more deep will I endart mine eye Than your consent ...

*April 5, 2016*

**Math**

The six faces of a fair cube are numbered 1 to 6. If the cube is rolled 300 times,what is the expected number of a 3 will land face up

*March 18, 2016*

**Geometry**

A model is made of a car. The car is 9 feet long and the model is 6 inches long. What is the ratio of the length of the car to the length of the model?

*March 17, 2016*

**Algebra**

Simplify (6x^-2)^2(0.5x)^4. I have no idea how to do this!, please help!

*February 9, 2016*

**Math**

735

*January 7, 2016*

**Math**

105

*January 7, 2016*

**Math**

8—(-2)

*January 6, 2016*

**Science**

so the answer would be 10.0 ?

*January 6, 2016*

**Science**

F/M=A So A=50/5.0 ? Am I correct ?

*January 6, 2016*

**Science**

Assuming a force of 50 N is applied to each object by each contestant, what is the acceleration of object A?_ B?_C?_ ( Person A's object is 5.0kg, person B's object is 2.5kg and C's is 0.5kg

*January 6, 2016*

**Health PlZ HELP MEE!!!**

You are correct for both answers.

*January 6, 2016*

**Physics**

A 2.6 kg rock is initially at rest at the top of a cliff. Assuming the rock falls into the sea at the foot of the cliff and that its kinetic energy is transferred entirely to the water, how high is the cliff if the temperature of 0.98 kg of water is raised 0.10°C? (Neglect...

*January 5, 2016*

**PHYSICS**

I'm just trying to look at the answers? How did i get here?

*November 3, 2015*

**Chemistry**

If your aspirin sample has an absorbance of 0.500 in a 1.00 cm cell, what will be its absorbance in a 1.50 cm cell. What would be the percent change in the absorbance if you used the larger cell and didn’t factor in the change in path length? The equation is y = 0.148X-0....

*October 27, 2015*

**chemistry**

What mass of water can be heated from 45C to 88C with 28 kj?

*October 23, 2015*

**vocab (english)**

sentence check 1 chapter 16 answer key

*October 19, 2015*

**Math**

a cell phone company offers the following plan: monthly charge (which includes 500 minutes) for $40 and a charge for additional minutes will be 5 cents a minute. write a piecewise function function putting x&y terms that can be used in any # or minutes. I am coming up with y=....

*October 17, 2015*

**AP Physics**

Two blocks are connected by a string over a frictionless, massless pulley such that one is resting on an inclined plane and the other is hanging over the top edge of the plane. The hanging block has a mass of 16 kg and the one on the plane has a mass of 8 kg. The coefficient ...

*October 15, 2015*

**Chemistry**

Describe in words how you would make a 1.00 M solution of HCl from a 5.00 M solution of HCl. Completely stumped here. Any help?

*September 26, 2015*

**math**

Laura drove to the mountains last weekend. There was heavy traffic on the way there, and the trip took 6 hours. When Laura drove home, there was no traffic and the trip only took 4 hours. If her average rate was 22 miles per hour faster on the trip home, how far away does ...

*September 23, 2015*

**math**

that isn't even an option thank you for the help

*July 22, 2015*

**math**

A135, 135A, 1A35, 13A5 A113, A123, A133, A143 0A23, 0a23,02A3, 02a3 1234, 5678, 0246, 1357

*July 15, 2015*

**Language Arts**

lee is wrong

*April 23, 2015*

**history**

is it a?

*April 22, 2015*

**history**

17. Under Franklin Roosevelt's Good Neighbor policy, A. the collective security among the nations of the Western Hemisphere declined. B. American commerce with Latin America increased, but only slightly. C. the Platt Amendment was rescinded. D. Cordell Hull favored ...

*April 22, 2015*

**Math**

There are 47 students in the marching band. There are 5 students in te first row, and the rest are in equal rows of 6. How many students are in each of the 6 rows?

*March 22, 2015*

**Social Studies**

is c.

*February 25, 2015*

**math**

Divide the 3 plants by 2 and you will get 44rows

*February 3, 2015*

**history**

Which statements describe the Persian Empire? Choose all answers that are correct. A. Darius I conquered all of Greece after defeating Athens at the Battle of Marathon. B. The Persians looked down on the culture and knowledge of the peoples they conquered. C. Cyrus oversaw a ...

*January 27, 2015*

**Science**

conduction

*January 12, 2015*

**Algebra ASAP thx**

I Thursday he read 81 pages

*December 15, 2014*

**Physics**

We always hear people say “You should conserve energy! Think of what will happen to the next generation if all our energy resources get depleted!” Is this in contradiction with the Law of Conservation of Energy which states that the total amount of energy in the ...

*December 2, 2014*

**algebra**

Solve system of equations to model the problem then solve: The length of a rectangle is 7 inches more than the width. The perimeter is 34 inches. Find the length and the width of the rectangle.

*November 27, 2014*

**Algebra**

Write a system of equations to model the problem and solve the system: The sum of two numbers is 156. What number is 28 more than the second number. What are the numbers?

*November 27, 2014*

**Algebra**

Write a system of equations to model the problem and solve the system: Benjamin has nickels and dimes and his toy bank he has a total of 45 coins the total value of $3.60. How many coins of each kind does he have?

*November 27, 2014*

**Algebra**

Write a system of equations to model the problem and solve the system: Benjamin has nickels and dimes and his toy bank he has a total of 45 coins the total value of $3.60. How many coins of each kind does he have?

*November 26, 2014*

**Algebra**

Write a system of equations to model the problem and solve the system: The sum of two numbers is 156. What number is 28 more than the second number. What are the numbers?

*November 26, 2014*

**algebra**

Solve system of equations to model the problem then solve: The length of a rectangle is 7 inches more than the width. The perimeter is 34 inches. Find the length and the width of the rectangle.

*November 26, 2014*

**Math**

A room measures 450cm by 350cm. Find the side if the largest square tile that can be used to tile without cutting

*November 20, 2014*

**Pre Calculus**

The logistic growth function P(t)= 160/ 1 + 9e^-0.165t describes the population of the endangered species of elk "t" years after they were introduced into the habitat. a. How many elk were initially introduced into the habitat? b. How many elk are expected after 6 ...

*November 20, 2014*

**Pre Calculus**

If a 25 mg sample of radioactive material decays to 18.4 mg in 5 years, how long will it take the sample to decay to 20.5 mg?

*November 20, 2014*

**Pre Calculus**

You invest $4500 into an account that earns 6.5% interest compounded monthly. How long will it take for the account to double in its value?

*November 20, 2014*

**Pre Calculus**

The population of a city is 127,000 and is decreasing by 2.4% each year. a. What will the population be in 10 years? b. Find when the population will be 95,000

*November 20, 2014*

**Chemistry**

Sort these species into isoelectronic groups. It doesn't matter which group goes in which box, so long as the correct species are grouped. Ne Mg2+ S2- Ti4+ K+ He Li+ Be2+ N3-

*November 6, 2014*

**Math**

Chris has a square garden with an area of 38.4 m squared. He decreases the length of each side by 1.7 m to make a smaller garden. What is the perimeter of the smaller garden. {Hint find the length of each side of the bigger garden first, then decrease the length, then find the...

*November 5, 2014*

**Physics**

1. A body was dropped from a building 10-m high. Its kinetic energy before reaching the ground is 980 J. What is the mass of the body? 2. A 1.0-kg block slides down a rough inclined plane whose height is 1.0 m. At the bottom the block has a speed of 4.0 m/s. Is mechanical ...

*October 21, 2014*