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:
\(3\ trucks\)
Step-by-step 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
\(x=5\ cars\)
\(y=3\ trucks\)