If $10$ men or $18$ boys can do a work in $15$ days,then the number of days required by $15$ men and $33$ boys to do twice the work is

$A$ and $B$ can complete a piece of work in $8$ days,$B$ and $C$ can do it in $12$ days,and $C$ and $A$ can do it in $8$ days. In how many days can $A, B,$ and $C$ together complete the work?

$A$ and $B$ can complete a piece of work in $30 \text{ days}$,$B$ and $C$ in $40 \text{ days}$,while $C$ and $A$ in $60 \text{ days}$. $A, B, C$ together can complete the work in (in $\text{days}$):

$A$ and $B$ can do a work in $12$ days. $B$ and $C$ can do the same work in $15$ days. $C$ and $A$ can do the same work in $20$ days. How much time will $A, B,$ and $C$ take to complete the same work together (in days)?

$A$ man and a boy received $Rs. 800$ as wages for $5$ days for the work they did together. The man's efficiency in the work was three times that of the boy. What are the daily wages of the boy? (in $Rs.$)

$4$ 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?