$A$ man,a woman,and a boy can complete a job in $3, 4,$ and $12$ days respectively. How many boys must assist $1$ man and $1$ woman to complete the job in $\frac{1}{4}$ of a day?

$A$ can complete a work in $10$ days,$B$ can complete the same work in $20$ days,and $C$ in $40$ days. $A$ starts working on the first day,$B$ works on the second day,and $C$ works on the third day. Again,$A$ works on the fourth day,$B$ on the fifth day,and so on. If they continue working in the same way,in how many days will the work be completed?

$7$ 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?

$4$ mat-weavers can weave $4$ mats in $4$ days. At the same rate,how many mats would be woven by $8$ mat-weavers in $8$ days?

$2$ men and $3$ women can complete a work in $10$ days,while $4$ men can complete it in $10$ days. In how many days will $3$ men and $3$ women complete the work?

$A$ 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 $days$)