A and B together do a piece of work in 12 days, B and C in 15 days, and C and A in 20 days. In how many days can they finish the work if all of them work together?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is Option 3 i.e. 10.
A and B together do a piece of work in 12 days, B and C in 15 days, and C and A in 20 days
L.C.M(12, 15, and 20) = 60
The efficiency of A and B = 60/12 = 5 units
The efficiency of B and C = 60/15 = 4 units
The efficiency of A and B = 60/20 = 3 units
The efficiency of all three = 2(A + B + C) = 12
(A + B + C) = 6
Time taken = 60/6 = 10 days