$6$ men or $12$ women can do a piece of work in $20$ days. In how many days can $8$ men and $16$ women do twice as big as this work?

If $12$ men and $16$ boys can do a piece of work in $5 \, \text{days}$,and $13$ men and $24$ boys can do it in $4 \, \text{days}$,then the ratio of the daily work done by a man to that of a boy is:

$A$ can do a piece of work in $120$ days and $B$ can do it in $150$ days. They work together for $20$ days. Then $B$ leaves and $A$ alone continues the work. After $12$ days,$C$ joins $A$ and the work is completed in $48$ days more. In how many days can $C$ do it if he works alone?

$A$ is thrice as good a workman as $B$ and therefore is able to finish a job in $60\, days$ less than $B.$ Working together,they can do it in (in $days$)

$A$ alone can complete a work in $18 \, days$ and $B$ alone in $15 \, days.$ $B$ alone worked at it for $10 \, days$ and then left the work. In how many more days will $A$ alone complete the remaining work?

$A$ and $B$ can do a piece of work in $12$ days and $15$ days,respectively. They began to work together,but $A$ left after $4$ days. In how many more days would $B$ alone complete the remaining work?