A and B can complete a piece of work in 15 days, B and C in 30 days and C and A in 45 days. In how many days will they complete the work if they start working together?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. .
A and B can complete a piece of work =15 days
B and C can complete a piece of work = 30 days
C and A can complete a piece of work = 45 days
Let's assume the total work = LCM = 15, 30, and 45 = 90
So, efficiency of A + B = 90/15 = 6 unit per day
efficiency of B + C = 90/30 = 3 unit per day
efficiency of C + A = 90/45 = 2 unit per day
So, they will complete the work = 90/(11/2) = 180/11 =