A and B can together finish a work in 30 days. They worked together for 20 days and then B left. After another 20 days, A finished the remaining work. In how many days can A alone finish the whole work?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 60
Given that
A and B can together finish a work = 30 days
After 20 days B left work.
According to the question
(A + B) × 30 = (A +B) × 20 + A × 20
(A + B) × 10 = A × 20
10 A = 10 B
A = B
Total work = (A + B) × 30 = 60 A
Now,
A can alone finish the whole work = 60 days