At a construction site, 15 men or 10 machines can construct a room in 66 days. In how many days can 5 men and 4 machines together complete the work?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 90.
Total work by 15 men = 15 × 66 = 990 units
Total work by 10 machines = 10 × 66 = 660 units
15 men = 10 machines
men/machine = 2/3
4 machines = 4 × 3/2 = 6 men
5 men + 4 machines = 5 + 6 = 11 men
Time = 990/11 = 90 days