A can complete a piece of work in 20 days and B can complete 20% of the work in 6 days. If they work together, in how many days can they finish 50% of the work, if they work together?
Show answer & explanation
Correct answer: A
Explanation
Correct Answer is option 1 i.e. 6
|
Understanding |
Application |
|
A completes a piece of work in 20 days. Then, Work done by A in 1 day = 1/20 B completes 20% of the work in 6 days. Then, B will complete 100% of the work in 6 × 100/20 = 30 days. Work done by B in 1 day = 1/30
|
When A and B work together: Work done by them in 1 day = 1/20 + 1/30 ⇒ (3 + 2)/60 ⇒ 5/60 = 1/12 ⇒ A and B working together can complete the whole work in 12 days. ∴ A and B together can complete 50% of the work in 12/2 = 6 days |