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A can do a piece of work in 45 days. He works at it for 5 days and then B completes it in 20 days. How long will A and B together take to complete the work?

A.	14 Ã— 1/3 days	B.	15 days
C.	13 Ã— 1/3 days	D.	14 days

Answer and Explanation

Answer:15 days

Explanation:
Explanation: In one day A does 1/45 of the work.
In 5 days A does 5/45 = 1/9 of the work
Remaining part of the work = 1 â€“ 1/9= 8/9
B takes 20 days to do 8/9 of the work.
In one day B will do 8 / 9Ã—20 = 2/45 of the work
Working together ( A & B ) will complete 1/45 + 2/45
= 3/45 = 1/15 of the work
They will take 45/3 days, i.e. 15 days

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