Multiple choice

480 persons working 10 hours per day complete one-fourth of a work in 10 days. How many additional persons are to be employed in order to complete the remaining work in 20 days, working 8 hours per day?

  1. 400

  2. 420

  3. 480

  4. 500

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Work done = 480 * 10 * 10 = 48000 man-hours for 1/4 work. Total work = 192000 man-hours. Remaining work = 144000 man-hours. Required men = 144000 / (20 * 8) = 144000 / 160 = 900. Additional men = 900 - 480 = 420.