Question

A and B together can complete a work in 10 days. B working alone can complete the work in 15 days. How long will it take for A alone to complete the work?
1. 25 days
2. 15 days
3. 20 days
4. 30 days

Answer 1

Correct Answer - Option 4 : 30 days

Given: 

A and B together can complete a work in 10 days

B working alone can complete the work in 15 days

Calculation:

A + B together can complete a work in a day = 1/10

B can complete a work in a day = 1/15

A can alone complete work in a day = 1/10 - 1/15 = 1/30

A can complete the total work in 30 days

∴ A can complete the total work in 30 days.