$A$ can do a piece of work in $24$ days,$B$ in $32$ days,and $C$ in $64$ days. All begin to do it together,but $A$ leaves $6$ days before the completion of the work. How many days did the work last?

How many $days$ will $1648$ persons take to construct a dam,if $721$ persons can build the same in $48$ days?

Bindal can finish a work in $10$ days. Jindal is twice as efficient as Bindal. If they work together,in how many days will the work be completed?

Twenty-four men can complete a work in sixteen $days$. Thirty-two women can complete the same work in twenty-four $days$. Sixteen men and sixteen women started working and worked for twelve $days$. How many more men are to be added to complete the remaining work in $2$ $days$?

$A$ is $4$ times as fast as $B$ and is,therefore,able to complete a work in $45$ $days$ less than $B$. $A$ and $B$,working together,can complete the work in (in $days$)

$P$ can complete a work in $12$ days working $8$ hours a day. $Q$ can complete the same work in $8$ days working $10$ hours a day. If both $P$ and $Q$ work together,working $8$ hours a day,in how many days can they complete the work?