Multiple choice

38 men working 6 hours a day can finish a work in 12 days. In how many days 57 people working 8 hours a day can finish double of the given work?

  1. 10

  2. 15

  3. 14

  4. 12

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

This is a work-rate problem using the concept of man-hours. Original work: 38 men x 6 hours x 12 days = 2736 man-hours. New work is double: 5472 man-hours. New arrangement: 57 people x 8 hours x D days = 456D man-hours/day. Equating: 456D = 5472, so D = 5472/456 = 12. The key formula is M1 x H1 x D1 = M2 x H2 x D2 for the same work, adjusting for 'double work' factor. Option D (12) is correct. Option A (10), B (15), and C (14) don't satisfy the equation.