Some staff promised to do a job in $18 \, days,$ but $6$ of them went on leave. So,the remaining men took $20 \, days$ to complete the job. How many men were there originally?

$A, B$ and $C$ can complete a work in $2 \, h$. If $A$ does the job alone in $6 \, h$ and $B$ in $5 \, h$,how long will it take for $C$ to finish the job alone? (in $h$)

$A$ and $B$ can do a piece of work in $18$ days,$B$ and $C$ in $24$ days,and $A$ and $C$ in $36$ days. In what time can they do it all working together? (in days)

Some carpenters promised to do a job in $9$ days,but $5$ of them were absent and the remaining men did the job in $12$ days. The original number of carpenters was:

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

$A$ man,a woman,and a boy can together complete a piece of work in $3$ days. If a man alone can do it in $6$ days and a boy alone in $18$ days,how long will a woman alone take to complete the work? (in days)