Ali, Avtar Singh and Ashok working together can finish a work in 8 days. Ali alone can do it in 20 days and Avtar Singh alone can do it in 24 days. In how many days can Ashok alone do the same work?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e 30.
Given that
Ali alone can do it in 20 days
Avtar Singh alone can do it in 24 days
Ali, Avtar Singh and Ashok working together can finish a work in 8 days
Total work = LCM (20, 24, 8) = 120
The efficiency of Ali = 120/20 = 6
The efficiency of Avtar = 120/24 = 5
The combined efficiency of all = 120/8 = 15
So. the efficiency of Ashok = 15 - (6 + 5) = 15 - 11= 4
Hence, the work is completed by Ashok alone in = 120/4 = 30 days