A and B together can do a piece of work in 20 days, while B alone can finish it in 25 days. How many days will A take to complete the same work alone?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 100
Given that
A and B can do a work in 20 days
B alone finish that work in 25 days
According to the question
⇒ (A + B) × 20 = B × 25
⇒ (A + B)/B = 25/20 = 5/4
The efficiency of (A + B) = 5
The efficiency of B = 4
The efficiency of A = 5 - 4 = 1
Total work = 5 × 20 = 100
Hence, A will take to complete the work = 100/1 = 100 days