Correct Answer: Option B
A's 2 day's work = ((1/20) x 2) = 1/10
(A + B + C)'s 1 day's work = (1/20+1/30+1/60)
=6/60 = 1/10
Work done in 3 days = (1/10 + 1/10)= 1/5
Now, 1/5 work is done in 3 days.
So, Whole work will be done in (3 x 5) = 15 days.
Download our app for free and access thousands of MCQ questions with detailed solutions