A can finish a work in 24 days, B in 9 days and C in 12 days. B and C start the work but are forced to leave after 3 days. The remaining work was done by A in:
5 days
6 days
10 days
10$ \dfrac{1}{2} $days
Explanation:
$\left(B + C\right)$s 1 days work =$ \left(\dfrac{1}{9} +\dfrac{1}{12} \right) $=$ \dfrac{7}{36} $.
Work done by B and C in 3 days =$ \left(\dfrac{7}{36} \times 3\right) $=$ \dfrac{7}{12} $.
Remaining work =$ \left(1 -\dfrac{7}{12} \right) $=$ \dfrac{5}{12} $.
Now,$ \dfrac{1}{24} $work is done by A in 1 day.
So,$ \dfrac{5}{12} $work is done by A in 24 $\times \dfrac{5}{12} $= 10 days.