A and B together can do a piece of work in 20 days, and B and C together can do the same work in 100 days. If B alone can do the same work in 140 days, then in how many days will A and C together can complete the same work?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. 175/8 days.
A and B together can do a piece of work in 20 days, B alone can do the same work in 140 days and B and C together can do the same work in 100 days
L.C.M(20, 140 and 100) = 700
The efficiency of A and B = 700/20 = 35 units
The efficiency of B = 700/140 = 5 units
The efficiency of B and C = 700/100 = 7 units
So, The efficiency of C = 7 - 5 = 2 units
And, The efficiency of A = 35 - 5 = 30 units
Time taken by A and C = 700/(30 + 2) = 700/32 = 175/8 days