Question

A can do a piece of work in 16 days and B can finish it in 20 days. They work together for 4 days and then A leaves. In how many days will B finish the remaining work ?

Answer 1

SOLUTION-

Time taken by A to finish the work = 16 days

⟹ Work done by A in one day = $\dfrac{1}{16}$

Time taken by B to finish the work = 20 days

⟹Work done by B in one day = $\dfrac{1}{20}$

Work done by ( A + B ) in one day

$⟹( \dfrac{1}{16} + \dfrac{1}{20})$

$⟹\dfrac{9}{80}$

★ Work done by ( A + B ) in four day

$⟹ \dfrac{9}{80} \times 4 = \dfrac{9}{20}$

Remaining work = $(1 - \dfrac{9}{20} ) = \dfrac{11}{20}$

Now , 1/20 of work is done by B in 1 day.

★ the complete work is done by B in 1 ÷ $\dfrac{1}{20}$ days

★ $\dfrac{11}{20}$ of work will be done by B in $(20 \times \dfrac{11}{20} )$ days = 11 days

Hence , B will finish the remaining work in 11 days.

Answer 2

Answer:

B will finish the remaining work in 11 days