A and B can complete a piece of work in 12 days. B and C can complete the same work in 15 days and C and A in 10 days. How many days will A take to complete the work by himself?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. .
We know,
Total work = Time × Efficiency
Now,
Total work (LCM of 12, 15, and 10) = 60 units
Efficiency of (A + B) = 60/12 = 5 unit/day
Efficiency of (B + C) = 60/15 = 4 unit/day
Efficiency of (C + A) = 60/10 = 6 unit/day
Efficiency of (A + B + C) = 15/2 = 7.5 unit/day
Efficiency of A = Efficiency of (A + B + C) - Efficiency of (B + C) = 7.5 - 4 = 3.5 unit/day
Required number of days = 60/3.5 =