Given that a small metal shop operates 10 hours each day, producing 100 parts/hour, if productivity were increased by 20%, how many hours would the plant have to work to produce 1000 parts?

A) less than 2 hours
B) between 9 and 10 hours
C) between 2 and 6 hours
D) between 6 and 8 hours
E) between 8 and 9 hours

The correct option is D) between 6 and 8 hours. With a 20% increase in productivity, the small metal shop producing 120 parts/hour would have to operate just over 8 hours to produce 1000 parts, placing the answer within the range of D) between 6 and 8 hours.

Explanation:

The correct option is D) between 6 and 8 hours. If a small metal shop operates 10 hours each day, producing 100 parts/hour, a 20% increase in productivity would mean the shop is now producing 120 parts/hour (20% of 100 parts = 20 parts; 100 parts + 20 parts = 120 parts/hour). To produce 1000 parts at this increased rate of productivity, we would divide the total parts needed by the new production rate per hour.

1000 parts ÷ 120 parts/hour = 8.33 hours.

Therefore, the shop would need to work a little over 8 hours to produce 1000 parts. This means the answer is D) between 6 and 8 hours.