$A$ certain job was assigned to a group of men to do in $20$ days. But,$12$ men did not turn up for the job and the remaining men did the job in $32$ days. The original number of men in the group was:

$A$ and $B$ together can complete a work in $12$ days. $A$ alone can complete it in $20$ days. If $B$ does the work only for half a day daily,then in how many days will $A$ and $B$ together complete the work?

If $3$ men or $5$ women can reap a field in $43$ days,how long will $5$ men and $6$ women take to reap it? (in days)

$A$ can do a job in $6 \, days$ and $A$ and $B$ can do it together in $2 \, days.$ How many $days$ will be taken by $B$ to do the job alone?

$A$ and $B$ can separately complete a piece of work in $20$ days and $30$ days respectively. They worked together for some time,then $B$ left the work. If $A$ completed the rest of the work in $10$ days,then for how many days did $B$ work?

$A$ work can be completed by $P$ and $Q$ in $12$ days,$Q$ and $R$ in $15$ days,and $R$ and $P$ in $20$ days. In how many days can $P$ alone finish the work?