Question

a can do a work in 12 days and b in 18 days. if they work on it together for 4 days then the fraction of the work that is left is :

Answer 1

Given, A can do work in = 12 days

B can do work in = 18 days

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A's 1 day work = 1/12

B's 1 day work = 1/18

1 day work of A and B together = 1/12 + 1/18

= (3+2) / 36 = 5/36

Work completed by A and B together in 4 days = 4 x 5/36

= 5/9

Work remaining = 1 - 5/9 = 4/9

Hence fraction of work that is left is 4/9

Answer 2

Hey !!

Refer to the attachment !!