SOLUTION: I need some help with this function: The cost of apples varies directly with as the amount purchased in pounds. If Sally spent $8.96 on 7 pounds of apples, how much did Ted spe

Algebra ->  Rational-functions -> SOLUTION: I need some help with this function: The cost of apples varies directly with as the amount purchased in pounds. If Sally spent $8.96 on 7 pounds of apples, how much did Ted spe      Log On


   



Question 1003252: I need some help with this function:
The cost of apples varies directly with as the amount purchased in pounds. If Sally spent $8.96 on 7 pounds of apples, how much did Ted spend on 5 pounds?

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
The cost of apples varies directly with as the amount purchased in pounds.
If Sally spent $8.96 on 7 pounds of apples, how much did Ted spend on 5 pounds?
:
A couple ways to do this
:
This way seems the most logical
Find the cost of 1 pound of apples
8.96/7 = $1.28 per pound
then find how much for 5 lb
5 * 1.28 = $6.40
:
you can also do it as a ratio relationship of direct variation
let a = cost for 5 lb
a%2F8.96 = 5%2F7
Cross multiply
7a = 8.96 * 5
7a = 44.80
a = 44.80/7
a = $6.40