A and B can individually complete a piece of work in 18 days and 30 days, respectively. A and B started working together, but A left 16 days before the work is completed and B alone completed the rest of the work. For how many days did A work?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. 5.
Calculations:
A and B can individually complete a piece of work in 18 days and 30 days, respectively
Total work (L.C.M of 18 and 30) = 90 units
The efficiency of A = 90/18 = 5
The efficiency of B = 90/30 = 3
Work done by B = 50/3 × 3 = 50 units
Remaining work = 90 - 50 = 40 units
These 40 units of work is done by both A and B
Time taken = 40/(5 + 3) = 40/8 = 5 days