A, B and C can complete a work in 60, 30 and 20 days, respectively. In how many days can A complete the work if he is assisted by B and C together on every fifth day?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 30.
Calculations:
Let the total work = 60 units (LCM of 60, 30 and 20)
Efficiency of A = 60/60 = 1
Efficiency of B = 60/30 = 2
Efficiency of C = 60/20 = 3
Work done in 5 days when B and C assist A on every 5th day = 1 + 1 + 1 + 1 + 6 = 10 units
Now the work will be completed;
5 days = 10 units
30 days = 60 units
Hence, total required days is 30.