Question

You and your friend each start a car-washing service. You spend $25 on supplies and charge $10 per car. Your friend spends $55 on supplies and charges $13 per car. How many cars do you have to wash to earn the same amount of money as your friend? Math item stem image

Answer 1

The answer is 10 cars

Answer 2

Explanation:

Alright, lets get started.

Suppose number of cars to be washed is x

You are charging $10 per car, so profit of yours after subtracting the supplies =
`10x -25`

Your friend is charging $ 13 per car, so his profit after subtracting the supplies =
`13x-55`

Both the amount earned are same, so

`10x-25=13x-55`

`3x=30`

`x=10`

hence, you are washing 10 cars. : Answer

Hope it will help :)