$A$ 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 (in $days$):

$A$ and $B$ can do a work in $8$ days,$B$ and $C$ can do the same work in $12$ days. $A, B$ and $C$ together can finish it in $6$ days. $A$ and $C$ together will do it in (in days):

$P$ can complete $\frac{1}{4}$ of a work in $10$ days,$Q$ can complete $40\%$ of the same work in $15$ days,$R$ can complete $\frac{1}{3}$ of the work in $13$ days,and $S$ can complete $\frac{1}{6}$ of the work in $7$ days. Who will be able to complete the work first?

While working $7$ hours a day,$A$ alone can complete a piece of work in $6$ days and $B$ alone in $8$ days. In what time would they complete it together,working $8$ hours a day? (in days)

$A, B$ and $C$ can complete a piece of work in $15, 30$ and $40$ days respectively. They started the work together,but $A$ left $2$ days before the completion of the work and $B$ left $4$ days before the completion of the work. In how many days was the work completed?

$A$ takes three times as long as $B$ and $C$ together to do a job. $B$ takes four times as long as $A$ and $C$ together to do the work. If all the three,working together,can complete the job in $24$ days,then the number of days $A$ alone will take to finish the job is: