Correct option is C
Given:
5 men or 9 children can finish a task in 92 days.
Formula Used:
Total work done = number of days efficiency
Solution:
Let efficiency of man = m
Let efficiency of boys = b
According to question
m:b =9:5
Total work done = =4140
Efficiency of 20 men and 10 boys = =230
Time take to complete the work = 4140/230 = 18 days