A small metal shop operates 10 hours each day, producing 100 parts/hour. If productivity were increased 20%, how many hours would the plant have to work to produce 1000 parts?

The plant would have to work 8.33 hours

Explanation:

Initial productivity:

100 parts were produced in 1 hour

Percentage increase in productivity = 20%

New productivity:

100 + (100 * 0.2) = 100 + 20 = 120

120 parts would be produced in 1 hour

Number of hours the plant would have to work to produce 1000 parts = 1000/120 = 8.33 hours