Question

Suppose that the number of cars manufactured at an automobile plant varies jointly as the number of workers and the time they work. If 160 workers can produce 32 cars in 2 hours, find the number of cars that 220 workers can produce in 3 hours.

Answer 1

They'll build 66 cars in those conditions.

Explanation:

In this case we can use a compounded rule of three to solve the problem. We need to set it up as shown bellow:

160 workers -> 32 cars -> 2 hours

220 workers -> x cars -> 3 hours

If the number of workers rise, then we expect the number of cars to rise aswel, so they're directly proportional. If the number of hours worked increase we can expect the number of cars to increase aswell, so they're directly proportional. We can now set the fractions:

(160*2)/(220*3) = 32/x

320/660 = 32/x

x = (32*660/320) = 66 cars

They'll build 66 cars in those conditions.