A and B can do a piece of work in 36 days. B and C can do the same work in 60 days, A and C do the same work in 45 days. In how many days can A alone complete the same work ?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 60.
A and B can do a piece of work = 36 days.
B and C can do the same work = 60 days
A and C can do the same work = 45 days.
Total work = LCM of 36, 60, and 45 = 180
Efficiency
A + B = 5......(1)
B + C = 3.......(2)
A + C = 4.......(3)
Add all three equations
2(A + B + C) = 12
A + B + C = 6.......(4)
Eq (2) are subtracted from (4).
Efficiency of A = 3
Time taken by A to finish the task alone = 180/3 = 60 days