# Algebra 1--Please, help me!

1. The number of calculators Mrs. Hopkins can buy for the classroom varies inversely as the cost of each calculator. She can buy 24 calculators that cost \$60 each. How many calculators can she buy if they cost \$80 each?

A: ?

2. Jeffs builds model train layouts. He has \$75 to spend on packages of miniature landscape items. He receives 6 free packages with each order. The number of packages y that Jeff can buy is given by y = 75/x + 6, where x represents the cost of each package in dollars. Describe the reasonable domain values and graph the functions.

A: Both the number of packages and the cost of each package in dollars will be nonnegative, so the nonnegative vlaues are reasonable for the domain and range.

Graph: ?

3. Suppose a cone and a cylinder have the same radius and that the slant height l of the cone is the same as the height h of the cylinder. Find the ratio of the cone's surface area to the cylinder's surface area.

Area of cone: S = πrl + πr^2

Area of cylinder: S = 2πrh + 2πr^2

1. 👍 0
2. 👎 0
3. 👁 77
1. #1 we have n calculators that cost c each.
Since nc = k is constant,
24*60 = 80n

#2
Actually, the cost must be a positive integer divisor of 75, since the number of packages must be an integer.

#3
well, you have the formulas, and you want the ratio

scone/scyl = (πrl + πr^2)/(2πrh + 2πr^2)
= πr(l+r) / 2πr(h+r)
= (l+r) / 2(h+r)

1. 👍 0
2. 👎 0
posted by Steve

## Similar Questions

1. ### algebra

the number of calculators mrs. hopkins can buy for the classroom varies inversely as the cost of each calculator. she can buy 24 calculators that cost \$60 each. how many calculators can she buy if they cost \$80 each?

asked by s on May 30, 2013
2. ### algebra1

Lisa wants to purchase calculators. At one store, she can buy a set of 5 calculators for \$80.00, or she can buy 24 calculators for \$264.00 at another store. a) Which store provides Lisa with a better buy? b) Is it possible that

asked by rosalie danenberg on October 28, 2010
3. ### Inverse Variation

Help me please.. Explain also :( 1. E is inversely proportional to Z and Z = 4 when E = 6. 2. P varies inversely as Q and Q = 2/3 when P = 1/2. 3.R is inversely proportional to the square of I and I = 25 when R = 100. 4. F varies

asked by Elmo Schnittka on November 9, 2011
4. ### maths(am i right??)

Ms James buys x calculators and y folders to sell, she must buy at least 5 calculators,the folders she buys must be at least twice the number of calculators and if each calculator cost \$20 and foldr \$5 and she cant spend more than

asked by cynthia on May 19, 2008
5. ### Math-Algebra

1. The length of a rectangle with a constant area varies inversely as its width. The length of this rectangle is 8in when its width is 3in. Find the length when the width is 4in. 2. The number of people working on a certain job

asked by Mckenna Louise on November 24, 2013
6. ### Pre-Algebra

If y varies directly with x, find the constant of variation with x = 4 and y = -24 If y varies inversely with x, find the constant of variation with x=5 and y = 10 If y varies directly with x, and y = 35 when x = 5 , find x when y

asked by Anon on June 7, 2015
7. ### math

A manufacturer of calculators would like to separate defective calculators from calculators that are acceptable. Through an error, a shipment of 12 calculators is sent out containing 3 defective calculators and 9 working

asked by Jenna on October 28, 2016
8. ### Math

A school planned to buy x calculators for a total cost of Ksh 16200. The supplier agreed to offer a discount of Ksh 60 per calculator. The school was the able to get three extra calculators for the same amount of money. (a) Write

asked by Anonymous on October 15, 2012
9. ### Algebra

A school planned to buy x calculators for a total cost of Ksh 16200. The supplier agreed to offer a discount of Ksh 60 per calculator. The school was the able to get three extra calculators for the same amount of money. (a) Write

asked by Anonymous on October 15, 2012
10. ### Math

If 10 classes in 10 schools receive 10 calculators each, which expression (10+10+10 or 10x3 or 1000 ) represent the amount of calculators the school discrit will buy.

asked by A on October 5, 2015

More Similar Questions