Question

Evan washes two types of vehicles. It takes him 30 minutes to wash a car and 40 minutes to wash a truck. He charges $12 to wash a car and $15 to wash a truck. In 270 minutes, Evan made $105 washing cars and trucks. How many trucks did Evan wash?

Answer 1

the answer is 3 i think

Answer 2

`3\ trucks`

Explanation:

Let

x-----> the number of cars

y----> the number of trucks

we know that

`30x+40y=270` -----> equation A

`12x+15y=105` -----> equation B

Using a graphing tool

Remember that the solution of the system of equations is equal to the intersection point both graphs

In this problem the intersection point is
`(5,3)`

see the attached figure

therefore

`x=5\ cars`

`y=3\ trucks`