Question

Mr. Schwartz builds toy cars. He begins the week with a supply of 85 wheels, and uses 4 wheels for each car he builds. Mr. Schwartz plans to order more wheels once he has fewer than 40 wheels left.

Answer 1

When will he have less than 40 wheels left? Well you can make the equation...

85-4x=40

And then solve for x.

85-4x=40

-4x=-45

x=11 1/4 rounded up to 12

answer: He will have less than 40 wheels left after he has built 12 cars.