Please solve this quick word problem?

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2 Answers
Jan 14, 2018

12 hours

Explanation:

Assume that all the workers have the same speed and efficiency.

If it takes 8 hours for 15 people, it will take 3 times more time for 1/3 of the people (i.e. 5 people) to complete the work. Which means 24 hours.

However, the question asks for the time needed for HALF the work. So, if it takes 24 hours for 5 people to FINISH the work, it will take then half the time to finish half the work (i.e. 12 hours).

Jan 14, 2018

12 hours

Explanation:

15 workers take 8 hours for all of the work

15 workers take 8/2 hours for half of the work

5 workers take 8*3 hours for all of the work

5 workers take (8*3)/2 hours for half of the work

8*3/2 = 12