Given, 6 men and 8 boys can complete the task in 10 days, and 26 men and 48 boys can finish it in just 2 days, how long will it take for 15 men and 20 boys to do the same work?
Show answer & explanation
Correct answer: A
Explanation
Given:
6 men + 8 boys → 10 days
26 men + 48 boys → 2 days
Let us assume that
1 man's work in 1 day = m
1 boy's work in 1 day = b
(6m + 8b) × 10 = total work
(26m + 48b) × 2 = total work
Both will be equal
10(6m + 8b) = 2(26m + 48b)
60m + 80b = 52m + 96b
8m = 16b
m = 2b
Total work = 10(6 × 2b + 8b) = 200b
1 day's work by 15 men + 20 boys
= 15 × 2b + 20b = 50b
Time = Total work / Work per day
= 200b / 50b = 4 days