Working together A, B and C can complete a task in 12 days. A and B can do the task in 55 days and 66 days respectively if they worked alone. In how many days can C do the task if he worked alone?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is Option 3 i.e. 20
Efficiency of C = 35 – (12 + 10)
= 33
Time required by C only = 
= 20 days