Question

You build and sell toy cars for $36 each. So far, you have built 25 toy cars. How many more toy cars will you have to build and sell to earn $1,620?

Answer 1

you need to build 20 more toy cars

Answer 2

36 × 25 = 900 and 36 × 20 = 720
720 + 900 = 1620
So basically you'll need 20 more cars.