# Robin

Most popular questions and responses by Robin-
## math

How many pairs of integers $(b,c)$ satisfy the equation \[\frac{b + 7}{b + 4} = \frac{c}{9}?\]

*asked on September 15, 2015* -
## math

on a 10 question quiz you correctly answer four one point questions and five two point questions. you earn 87.5% of the possible points on the quiz. a. how many possible points is the quiz worth b. how many questions did you miss c. how many points was

*asked on March 1, 2018* -
## Physics

Oasis B is a distance d = 7.0 km east of oasis A, along the x axis shown in the figure. A confused camel, intending to walk directly from A to B instead walks a distance W1 = 22 km west of due south by angle θ1 = 15.0°. It then walks a distance W2 = 34

*asked on February 9, 2014* -
## Statistics

A group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spent studying per week. Assuming a standard deviation of 3 hours, what is the required sample size if the error should be

*asked on September 5, 2010* -
## College Algrebra

Joel can run around a 1/4 mi track in 66 sec. Jason can run around the track in 60 sec.If the runners start at the same point on the track and run in opposite directions, how long will it take the runners to cover 1/4 mile?

*asked on January 25, 2016* -
## Calculus

According to the National Health Survey, the heights of adult males in the United States are normally distributed with mean 69.0 inches and standard deviation 2.8 inches. A. What is the probability that an adult male chosen at random is between 61 inches

*asked on November 3, 2013* -
## READING

VOCABULAY/CONTEXT CLUES WHAT DOES COMBUSTION MEAN? wHAT CLUES HELP YOU TO DETERMINE THE MEANING? wHAT IS A WAFT? WHAT CLUES HELP YOU TO DETERMINE THE MEANING? HOW DOE CONTEXT CLUES HELP YOU DTERFMINE THE MEANING OF DINGY?

*asked on November 5, 2013* -
## math

you make homemade lip balm. About 11% of the lip balm is made from beeswax. You make 4 2/5 teaspoons of the lip balm. About how many teaspoons of beeswax do you need?

*asked on December 11, 2017* -
## math

the expression 1/4y+3/8 factored is?

*asked on November 1, 2017* -
## Physics

A hockey puck is sliding on frictionless ice. It slams against a wall and bounces back toward the player with the same speed that it had before hitting the wall. Does the velocity of the hockey puck change in this process?

*asked on September 15, 2011* -
## Physics

Some insects can walk below a thin rod (such as a twig) by hanging from it. Suppose that such an insect has mass m and hangs from a horizontal rod as shown in the figure, with angle θ = 37°. Its six legs are all under the same tension, and the leg

*asked on February 17, 2014* -
## Chemistry

two solutions are prepared using the same solute solution a: 0.27g of the solute disolves in 27.4g of t-butanol solution b: 0.23g of the solute disolves in 24.8g of cyclohexane which solution has the greatest freesing point change? show calculations and

*asked on February 18, 2013* -
## physics

A man doing push-ups pauses in the position shown in the figure . His mass m = 80 kg. In push up position: From hands to waist = 40 cm From waist to feet = 95 cm height - heel of foot to ground = 30 cm Determine the normal force exerted by the floor on

*asked on November 3, 2010* -
## Calculus

A cable hangs between two poles of equal height and 40 feet apart. At a point on the ground directly under the cable and x feet from the point on the ground halfway between the poles the height of the cable in feet is h(x)=10+(0.4)(x^1.5). The cable weighs

*asked on October 19, 2013* -
## math

There are 22 events at an indoor track and field meet. the ratio of track events to field events is 8:3. How many of the events are track events?

*asked on November 27, 2017* -
## math

you spend $16 on 3 notebooks and x binders. Notebooks cost $2 each and binders cost $5 each. Write an equation you can use to find the number of binders you bought.

*asked on February 12, 2018* -
## math

a figure is made up of a big square and 4 smaller identical squares. The area of the whole figure is 980 square inches. What is the unknown length?

*asked on May 21, 2018* -
## Chemistry!! Please help!

If the wavelength of line B is 142.5 nm, calculate the wavelength of line A. Line A is the transition of n=6 to n=3 Line B is the transition of n=5 to n=3

*asked on October 21, 2008* -
## math

solve the equation for y 8=3x+6y

*asked on September 4, 2019* -
## Physics

A particle starts from the origin at t = 0 and moves along the positive x axis. A graph of the velocity of the particle as a function of the time is shown in the figure; the v-axis scale is set by vs = 7.0 m/s. (a) What is the coordinate of the particle at

*asked on February 5, 2014* -
## math

R. H. Bruskin Associates Market Research found that 30% of Americans do not think that having a college education is important to succeed in the business world. If a random sample of five Americans is s selected, find these probabilities. (a) Exactly two

*asked on June 20, 2013* -
## physical science

a car has a mass of 1000kg and accelerates at 2m/s/s. What is the magnitude of the force exerted on the car.

*asked on September 10, 2008* -
## math

One third of the viewers at a movie opening rated the movie as Good or Very Good. Thirty-five people rated it Good and twenty people rated it Very Good. Write and solve an equation to find the number of people p in the audience.

*asked on March 20, 2018* -
## math

A gallon jug of milk is 3/4 full. After breakfast the jug is 1/12 full. Find the difference of the amounts before breakfast and after breakfast.

*asked on October 22, 2018* -
## Chemistry

Adding 1.00 g of benzene, C6H6, to 80 g of cyclohexane, C6H12, lowers the freezing point of the cyclohexane from 6.5 to 3.3 degree celsius. What is the value of kf for cyclohexane?

*asked on December 2, 2015* -
## Calculus

The position vector for a proton is initially r(with vector sign above it) =5.0i(with top)- 6.0j(with top) + 2.0k(with top) and then later is r vector = -2.0i(with top)+6.0j(with top)+ 2.0k (with top), all in meters. What is the proton's displacement

*asked on September 26, 2013* -
## Chemistry

Explain why the solubility of PbF2 is pH dependent, but the solubility of PbCl2 is not. I know the solubility of PbF2 is pH dependent because the solubility would increase as the solution becomes more acidic because the F^- ion is the conjugate weak base

*asked on April 11, 2016* -
## Chemistry AP

what does this mean (we are on quantum) The figure below represents part of the emission spectrum for a one-electron ion in the gas phase. All the lines result from electronic transmissions from excited states to the n = 3 state. the graph is like this A B

*asked on October 21, 2008* -
## math

you are creating identical candy bags using 18 chocolate bars and 30 peanut butter cups. What is the greatest number of bags you can fill using all the candy?

*asked on August 4, 2018* -
## math

Jay spent 6 hours playing games, studying and talking with his friends. he spent 2/5 of the time playing games and 1/2 of the time studying. how many minutes did he spend talking with his friends?

*asked on February 27, 2019* -
## math

6 1/2 - 7/8 divided by 5 11/16

*asked on September 27, 2018* -
## math

A hurricane has wind speeds that are greater than or equal to 74 miles per hour. Write an inequality to represent the possible wind speeds during a hurricane.

*asked on March 20, 2018* -
## English 2

Water that aids digestion is really true.Identify the function of the noun clause.

*asked on February 4, 2015* -
## Calculus

A rancher wants to make a rectangular pen to house her animals. She will divide it up with 3 fences down the middle parallel to one side. If she has 14000 ft of fencing to work with, what are the dimensions of the pen of greatest area? Width = Length =

*asked on July 13, 2013* -
## Physics

A uniform, 274-N rod that is 2.05m long carries a 225-N weight at its right end and an unknown weight W toward the left end.When W is placed 50.3cm from the left end of the rod, the system just balances horizontally when the fulcrum is located 78.0cm from

*asked on April 12, 2015* -
## Chemistry

Titration of Na2CO3 with HCl. (pKa1(H2CO3) = 6.352, pKa2(H2CO3) = 10.329) . Calculate the pH at each of the following volumes of 0.20 M HCl added to 20.00 mL of 0.10 M Na2CO3. I figured out everything except for adding 20.00 ml of 0.20M HCL. Please help

*asked on March 23, 2015* -
## Calculus

Evaluate the integral below by interpreting it in terms of areas. In other words, draw a picture of the region the integral represents, and find the area using geometry. ç6 −6 36−x^2dx

*asked on July 15, 2013* -
## math

A section of a boardwalk is made using 15 boards. Each board is 9.25 inches wide. The total width of the section is 144 inches. The spacing between each board is equal. What is the width of the spacing between each board?

*asked on September 3, 2019* -
## physics

a geosynchronous satellite orbits at a distance from earth's center of about 6.6 earth radii and takes 24 h to go around once. what distance in meters does the satellite travel in one day? what is its orbital velocity in m /s?

*asked on November 25, 2010* -
## math

you buy a ring box as a birthday gift that is in the shape of a triangular prism. What is the least amount of wrapping paper needed to wrap the box? The lengths of the box are 14.5 cm, 8 cm, 10 cm, 10.5 cm

*asked on March 21, 2019* -
## math

Matthew used 1/5 of a box of flour for cooking and 3/4 of the remainder to make bread. The rest of the flour was packed equally into 5 containers. What fraction of the total amount of flour was in each container?

*asked on March 7, 2018* -
## math

jill has 8 yards of cloth. she wants to cut it into pieces that are 1/4 yard long. How many pieces can she cut from the length of cloth

*asked on January 10, 2018* -
## Algebra

Form a third degree polynomial function with real coefficients such that -7 + i and -9 are zeros

*asked on March 21, 2016* -
## Calculus

Two cars start moving from the same point. One travels south at 60 mph and the other travels west at 25 mph. At what rate is the distance between the cars increasing 2 hours later? Let x = the distance covered by the south traveling car. Let y = the

*asked on June 28, 2013* -
## math

a store buys an item for $10. To earn a profit of $25 what percent does the store need to markup the item?

*asked on January 14, 2019* -
## Physics

A roller coaster has a mass of 425 kg. It sits at the top of a hill with height 66 m. If it drops from this hill, how fast is it going when it reaches the bottom? (Assume there is no air resistance or friction.)

*asked on May 14, 2013* -
## chemistry

The reaction of chlorine gas with solid phosphorus (P4) produces solid phosphorus pentachloride. When 63.5 g chlorine reacts with 28.5 g P4, which reactant is limiting?

*asked on May 13, 2013* -
## math

factor out the coefficient of the variable 1/5k+15

*asked on September 4, 2019* -
## math

Bass: The bass in Clear Lake have weights that are normally distributed with a mean of 2.3 pounds and a standard deviation of 0.6 pounds. (a) If you catch one random bass from Clear Lake, find the probability that it weighs less than 1 pound? Round your

*asked on October 26, 2015* -
## Math

Rearrange this expression into quadratic form, ax2 bx c = 0 0.20= ((x^2)/(55-x)) where a = 1, and identify the values of b and c.

*asked on February 18, 2013* -
## Geography

Boundary would most likely cause the greatest political problems think about types of natural borders and artificial borders

*asked on September 23, 2019* -
## math

the selling price is $122.40 the mark up is 80% what is the cost to the store

*asked on April 3, 2019* -
## Calculus

Solve the separable differential equation 10x−6ysqrt(x^2+1)dy/dx=0. with the initial condition y(0)=4.

*asked on November 18, 2013* -
## science

what is data evidence in a science experiment

*asked on November 26, 2018* -
## math

you find a sales receipt from a store that shows the total price as $40, and the total amount paid including sales tax as $42. a. Write an equation you can use to find the sales tax rate r. b. Can you use r to find the percent for the sales tax?

*asked on February 12, 2018* -
## math

(-7x+13)-(6x+15)

*asked on October 9, 2019* -
## Math

The question is: Determine the surface area and volume of this cylinder, correct to one decimal point. The cylinder has a radius of 4 inches and the height is 3 yards. This site explains how to find the surface area and volume of a cylinder.

*asked on June 15, 2006* -
## Algebra

Gary has 3y comics. Shaun has 8 comics. They share their comics equally. How many comics does each of them have?

*asked on April 9, 2019* -
## math

13/2 - 7/8 x 16/91

*asked on September 27, 2018* -
## math

Write an equation for the following problem... you spend $16 on 3 notebooks and x binders. Notebooks cost $2 each and binders cost $5 each. Write an equation you can use to find the number of binders you bought.

*asked on February 12, 2018* -
## math

write the phrase as an expression... 7 more than the quotient of a number y and 5

*asked on October 24, 2017* -
## Physics

A single force acts on a 1.1 kg particle-like object in such a way that the position of the object as a function of time is given by x = 4.1t - 3.6t2 + 4.5t3, with x in meters and t in seconds. Find the work done on the object by the force from t = 0 to t

*asked on March 8, 2014* -
## Geography

Why do local and regional political systems exist

*asked on September 23, 2019* -
## math

In the continental United States, the ratio of states that border an ocean to states that do not border an ocean is 7 : 9. How many of the states border an ocean?

*asked on November 27, 2018* -
## Physics

A severe thunderstorm dumped 2.4 in of rain in 30 min on a town of area 35 km^2. What mass of water (in kg) fell on the town? One cubic meter of water has a mass of 103 kg.

*asked on January 30, 2014* -
## math

Two vertices of a triangle are F (1, −4) and G(6, −4). List two possible coordinates of the third vertex so that the triangle has an area of 20 square units.

*asked on February 5, 2018* -
## Math

Is -n always, sometimes, or never a positive number? Explain. I don't know what they mean by -n - is a negative number?

*asked on September 1, 2016* -
## Chemistry

A metal, , of atomic weight 96 reacts with fluorine to form a salt that can be represented as . In order to determine and therefore the formula of the salt, a boiling point elevation experiment is performed. A 9.18- sample of the salt is dissolved in 100.0

*asked on February 20, 2011* -
## MATH

A Ferris wheel completes one revolution every 90 s. The cars reach a maximum of 55 m above the ground and a minimum of 5 m above the ground. The height, h, in metres, above the ground can be modeled using a sine function, where t represents time, in

*asked on July 18, 2013* -
## math

write the fraction or mixed number as a percent 23/40

*asked on December 6, 2017* -
## math

I have 23 hundreds, 47 tens, 5 ones, 8 tenths and 10 hundredths. What number am I. We got the numbers to the left of the decimal - 2775 but to the right is it .81 or .18 or .9 as 10 hundredths is the same as 1 tenth so add 8 tenths and 1 tenth together?

*asked on January 28, 2015* -
## Physics

Two trains, each having a speed of s, are headed at each other on the same straight track. A bird that can fly at speed 2s flies off the front of one train when they are d apart and heads directly for the other train. On reaching the other train it flies

*asked on February 5, 2014* -
## math

s+1/4=4/8 solve the proportion

*asked on March 4, 2019* -
## math

Friday is a class field trip and all 32 students bring their lunch. Will themean for the whole week be greater than or less than the mean for Monday through Thursday? Find the new mean

*asked on April 15, 2019* -
## math

you earn 10 points for every coin you collect in a video game. Then you find a start that triples your score. Write an expression for the number of points you earn from the coins

*asked on October 26, 2017* -
## math

Elena has 12 pieces of banana bread. She gives an equal amount of banana bread to 5 friends. How many pieces of banana bread does she give each friend?

*asked on December 18, 2018* -
## PHYSICS ---HELP!

A man doing push-ups pauses. His mass is 80-kg. Determine the normal force exerted by the floor on each hand and on each foot. a = 40 cm b = 95 cm c = 30 cm W = mg = 784 N

*asked on November 2, 2010* -
## Chemistry

A metal, , of atomic weight 96 reacts with fluorine to form a salt that can be represented as . In order to determine and therefore the formula of the salt, a boiling point elevation experiment is performed. A 9.18- sample of the salt is dissolved in 100.0

*asked on February 20, 2011* -
## math

a color printer prints 28 pages in 12 minutes. How many pages does it print per minute

*asked on December 3, 2018* -
## math

Jerry is 50 inches tall growing at a rate of 1/24 inches per month. Adam is 47 inches tall growing at a rate of 1/8 per month. If they continue to grow at these rates for the next 4 years in how many months will they be the same height? Solve two different

*asked on April 14, 2014* -
## Physics

A vector with a magnitude of 17.6 m is directed at angle θ = 43o counterclockwise from the +x axis. What are the components (a) ax and (b) ay of the vector? A second coordinate system is inclined by angle θ' = 20o with respect to the first. What are the

*asked on February 9, 2014* -
## Calculus

A television camera is positioned 2500 ft from the base of a rocket launching pad. The angle of elevation of the camera has to change at the correct rate in order to keep the rocket in sight. Also the mechanism for focusing the camera has to take into

*asked on July 1, 2013* -
## Calculus

A television camera is positioned 2500 ft from the base of a rocket launching pad. The angle of elevation of the camera has to change at the correct rate in order to keep the rocket in sight. Also the mechanism for focusing the camera has to take into

*asked on June 28, 2013* -
## PHYSICS ---HELP!

A man doing push-ups pauses. His mass is 80-kg. Determine the normal force exerted by the floor on each hand and on each foot. a = 40 cm b = 95 cm c = 30 cm W = mg = 784 N

*asked on November 2, 2010* -
## chemistry

What is the mass of NaCl required to make 840. mL of solution having an osmotic pressure of 7.70 atm at 36.6°C? This is the approximate concentration of the saline solution used to rinse contact lenses.

*asked on May 28, 2019* -
## math

Each ticket to a school dance is $4. The total amount collected in ticket sales is $332. Write and solve an equation to find the number of students attending the dance.

*asked on March 20, 2018* -
## math

in a parking lot, 16% of the cars are blue. There are 4 blue cars in the parking lot. How many cars in the parking lot are NOT blue?

*asked on December 13, 2017* -
## Calculus

For the function f described by the following table, estimate ç40 0 f(x)dx using the following. Enter each answer as a sum to show your work. 5 left rectangles 5 right rectangles 5 midpoint rectangles x 0 4 8 12 16 20 24 28 32 36 40 y 7 -46 -50 45 -7

*asked on July 15, 2013* -
## Calculus

Find the point on the line 7x+5y−2=0 which is closest to the point (−6,−2).

*asked on July 15, 2013* -
## math

Zach had a rope that was 15 feet long. He cut it into 3 pieces. The first piece was 3.57 feet longer than the second piece. The third piece is 2.97 feet longer than the second piece. How long was the third piece of rope?

*asked on March 9, 2019* -
## math

On three 150point geography tests, you earned grades of 88%, 94%, and 90%. The final test is worth 250 points. What percent do you need on the final to earn 93% of the total points on all tests?

*asked on December 12, 2017* -
## Chemisty

object a has a specific heat of 0.568 j/[(g)(°C)] and object B has a specific heat of 1.34 J/[(g)(°C)]. which o ject A or B will heat up faster and why Is is A because it is closer to 0?

*asked on January 21, 2016* -
## math

victoria has a 2-pound package of flour. she uses 2/5 of the flour to make a pizza. She then uses 3/10 of the remaining flour to make bread. Find the weight of the package of flour that she has left. Express answer in decimal.

*asked on February 27, 2019* -
## Please help with Calculus??

Boxes are labeled as containing 500g of cereal. The machine filling the boxes produce weights that are normally distributed with standard deviation 12g. 1) Suppose a law states that no more than 5% of a manufacturer's cereal boxes can contain less than the

*asked on November 8, 2013* -
## math

X squared(x+1)

*asked on October 29, 2018* -
## Physics true false

true false The speed of a particle is always positive. True False The average speed of a particle is equal to the magnitude of its average velocity. True False The acceleration of a particle can be non-zero when its speed is constant. True False When the

*asked on February 26, 2013* -
## math

.31b=12

*asked on November 14, 2018* -
## Algebra

In a large city, taxicabs charge $4.00 for the first one-fifth mile and 0.38 for each additional one- fifth mile. Frank has only $8.50. What is the maximum distance he can travel?

*asked on October 21, 2017* -
## Physics

A 50.0-kg boy runs on a horizontal surface at a speed of 10.0 m/s and jumps onto a cart just before reaching a slope as shown in the figure. The cart is initially at rest. If the mass of the cart is 150 kg, what is the maximum height h the boy/cart will

*asked on May 24, 2016* -
## geometry

circle E with a diameter AC and m

*asked on April 24, 2015*