$12$ men and $16$ boys can do a piece of work in $5$ days. $13$ men and $24$ boys can do it in $4$ days. Then,the ratio of the daily work done by a man to that of a boy is:

$A$ can do a work in $15 \text{ days}$ and $B$ in $20 \text{ days}$. If they work together on it for $4 \text{ days}$,then the fraction of the work that is left is

$8$ men can complete a piece of work in $20$ days. $8$ women can complete the same work in $32$ days. In how many days will $5$ men and $8$ women together complete the same work?

Nikita,Nishita,and Kavita can complete a work in $2 \frac{2}{3}$ days. If Nishita and Kavita can complete it in $4$ days,and Nishita alone can do it in $6$ days,then in how many days can Nikita and Nishita complete the work?

$A, B$ and $C$ can do a piece of work individually in $8, 12$ and $15$ days,respectively. $A$ and $B$ start working,but $A$ quits after working for $2$ days. After this,$C$ joins $B$ until the completion of the work. In how many days will the work be completed?

If $6$ men and $8$ boys can do a piece of work in $10$ days and $26$ men and $48$ boys can do the same work in $2$ days,the time taken by $15$ men and $20$ boys to do the same type of work will be (in days)