If $12$ men or $18$ women can build a wall in $14$ days,then working at the same rate,$8$ men and $16$ women can build the same wall in how many days?

$A$ can do a piece of work in $12$ days and $B$ in $20$ days. If they together work on it for $5$ days and the remaining work is completed by $C$ in $3$ days, then in how many days can $C$ do the same work alone?

$A$ can do a certain work in $12$ days. $B$ is $60\%$ more efficient than $A$. How many days will $B$ and $A$ together take to do the same job?

$P$ and $Q$ can do a piece of work in $30$ and $40$ days respectively. They began the work together,but $P$ left after some days and $Q$ finished the remaining work in $12$ days. After how many days did $P$ leave?

$A$ and $B$ together can complete a work in $10$ days. They started together,but $A$ left after $2$ days and the remaining work was completed by $B$ in $12$ days. In how many days can $A$ complete the entire work while working alone?

$4$ girls can complete a piece of work in $8$ days,the same work $3$ boys can complete in $9$ days,$7$ men in $2$ days,and $5$ women in $4$ days. Who among them has the minimum capacity of work?