A alone can complete a work in 14 days and B alone can complete the same work in 21 days. A and B start the work together but A leaves the work after 4 days of the starting of work. In how many days B will complete the remaining work?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 11 days
A alone can complete a work in 14 days and B alone can complete the same work in 21 days
Let total work be LCM of 21, 14 = 42 units
Efficiency = Total work/Time
Efficiency of A = 42/14 = 3 Units
Efficiency of B = 42/21 = 2 Units
A/C to question
(3 + 2) × 4 + 2x = 42
2x = 42 - 20
2x = 22
x = 11 days