Correct option is B
Given:
9 men + 12 boys =4 days.
4 men + 16 boys = 6 days.
Solution:
Let the work done by 1 man in 1 day = M, and by 1 boy in 1 day = B.
(9M + 12B) 4 = (4M + 16B) 6
36M + 48 B = 24M + 96B
12M = 48B
M/B = 4/1
Total Work = (9M + 12B) 4 = (9 4 + 121)4 = 48 4
Time for 6 men and 24 boys =