A can do a piece of work in 10 days and B can do it in 12 days. They work together for 3 days. Then B leaves and A alone continues. 2 days after that C joins and the work is completed in 2 days more. In how many days can C do it, if he works alone?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 40 days
Let total work = 60 units
Now,
Remaining work done by A and C = 60 - 33 - 12 = 15 units
They do 15 units in 2 days
They do 15/2 unit/day
Out of 15 units, C does = 15/2 - 6 = 3/2 units/day
C alone can do work = 60/(3/2) = 40 days