Question

13. A can do a piece of work in 14 days, while B can do in 21 days. They begin together. But, 3 days
before the completion of the work, A leaves off. Find the total number of days taken to complete the work​

Answer 1

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HERE YOU GO

If A can do the wrok in 14 days, his work per day = 1/14.

if B can do the work in 21 days, his work per day = 1/21.

if A and B work together, work per day = (1/14)+(1/21) = 5/42.

Hence work will be completed, if and B work together = 42/5 = [ 8+(2/5) ] days.

SO THE ANSWER IS 8.5 Days

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