Question

A can complete a work in 24 days and B can complete the same work in 18 days. A and

B started doing the work together. After 4 days A discontinued working. How many days

would the work take to be completed?

Answer 1

Hi,

Answer:

> Work complete in 15 days.

> A and B together work for 4 days,B alone work for 11 days.

Solution:
*************

As A can complete a work in 24 days

A's one day work is 1/24 part

and B can complete a work in 18 days

B's one day work is 1/18 part


ATQ

Both A and B work for 4 days

In four day A and B together do
$\frac{4}{24} + \frac{4}{18} \\ \\ = \frac{1}{6} + \frac{2}{9} \\ \\ = \frac{3 + 4}{18} \\ \\ = \frac{7}{18}$

In four days 7/18 part is done,

part left of total work
$1 - \frac{7}{18} \\ \\ = \frac{18 - 7}{18} \\ \\ = \frac{11}{18}$
So,A left work after 4 days,remaining work has to be completed by B only,

Work left for B = 11/18

B's one day work is 1/18

So,B complete 11/18 part work in 11 days.

Hope it helps you.