Multiple choice

40 men can complete a work in certain number of days working 5 hours a day. If 10 more men joined and all the men work for 6 hours a day, then the work will be completed in 5 days less time than estimated. How many days in total it is required to complete the work?

  1. 8

  2. 10

  3. 12

  4. 15

  5. 16
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let original days be D. Work = 40 * 5 * D. New work = 50 * 6 * (D-5). 200D = 300(D-5) = 300D - 1500. 100D = 1500, D = 15.

AI explanation

Using the formula for man-hours, M1 x D1 x H1 = M2 x D2 x H2, we have 40 men working for D days at 5 hours a day. When 10 more men join, the new equation becomes 40 x D x 5 = 50 x (D - 5) x 6. Solving 200D = 300(D - 5) gives 200D = 300D - 1500, which simplifies to 100D = 1500 and D = 15. The total estimated time required is 15 days.

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