A man alone can do a piece of work in 16 days, but with the help of his friend, he can do it in 8 days. In what time can his friend do it alone?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 16 days.
Concept used:
Work = Efficiency × time
Calculations:
Total Work (LCM of 16 and 8) = 16 units
Efficiency of the man and his friend = 16/8 = 2 units/day
Efficiency of the man = 16/16 = 1 unit/day
Efficiency of the friend = 2 - 1 = 1 unit/day
Hence, the required number of days taken by the friend to do the work alone = 16/1 = 16 days