$4$ men or $6$ women can finish a piece of work in $20$ days. In how many days can $6$ men and $11$ women finish the same work?

$A$ can complete a work in $m$ days and $B$ can complete it in $n$ days. How many days will it take to complete the work if both $A$ and $B$ work together?

$A, B$ and $C$ completed a work costing $Rs. 1800$. $A$ worked for $6$ days,$B$ for $4$ days and $C$ for $9$ days. If their daily wages are in the ratio of $5: 6: 4$,how much amount will be received by $A$ (in $Rs.$)?

Kim can do a work in $3 \, \text{days}$ while David can do the same work in $2 \, \text{days}$. Both of them finish the work together and get $Rs. 150$. What is the share of Kim? (in $Rs.$)

$15$ men take $20$ days to complete a job working $8$ hours a day. How many hours a day should $20$ men work to complete the same job in $12$ days?

$A$ can do a work in $20 \, days$ and $B$ in $40 \, days$. If they work on it together for $5 \, days$,then the fraction of the work that is left is: