$7$ men can complete a piece of work in $12$ days. How many additional men will be required to complete double the work in $8$ days?

$A$ alone can complete a work in $16$ days and $B$ alone in $12$ days. Starting with $A$,they work on alternate days. The total work will be completed in (in days):

$P, Q$ and $R$ contract a work for $Rs. 550$. Together,$P$ and $Q$ are supposed to do $\frac{7}{11}$ of the work. How much does $R$ get? (in $Rs.$)

$A$ group of men decided to do a work in $10 \, days,$ but five of them absented themselves. If the rest of the group finished the work in $12 \, days,$ find the original number of men? (in $men$)

$A$ and $B$ can complete a piece of work in $45$ and $40$ days respectively. Both started to work together,but after some days $A$ left and $B$ alone completed the remaining work in $23$ days. For how many days did $A$ work?

$A$ and $B$ can complete a piece of work in $6$ days,and $A$ alone can complete it in $9$ days. The time taken by $B$ alone to complete the work is (in days):