$18$ boys can do a piece of work in $24$ days. In how many days can $27$ boys do the same work?

$A$ does half as much work as $B$ in $three-fourths$ of the time. If together they take $18$ days to complete a work,how much time shall $B$ take to do it alone? (in days)

$A$ contractor has the target of completing a work in $40 \text{ days}$. He employed $20$ persons who completed $\frac{1}{4}$ of the work in $10 \text{ days}$ and left. The number of additional persons he has to employ to finish the remaining part of the work as per the target is:

$A$ can lay railway track between two given stations in $16 \, days$ and $B$ can do the same job in $12 \, days$. With the help of $C$,they did the job in $4 \, days$ only. Then $C$ alone can do the job in (in $days$)

$P, Q$ and $R$ can do a piece of work in $60$ days,$100$ days and $80$ days respectively. They work together to finish the work and receive $Rs. 2256$. Then $P$ will get (in $Rs.$)

Anu can complete a work in $10$ days. Manu is $25\%$ more efficient than Anu,and Sonu is $60\%$ more efficient than Manu. Working together,how long would they take to finish the job? (in days)