$A$ and $B$ can do a piece of work in $30$ and $36$ days respectively. They began the work together,but $A$ leaves after some days and $B$ finished the remaining work in $25$ days. After how many days did $A$ leave?

$A, B$ and $C$ can do a piece of work in $16, 32$ and $48$ days,respectively. They started working together,but $C$ left after working $4$ days and $B$ left $2$ days before the completion of the work. The total number of days taken for the completion of the work was (in days):

Working $7\, \text{hours}$ daily,$24$ men can complete a piece of work in $27$ $\text{days}$. In how many $\text{days}$ would $14$ men complete the same piece of work working $9\, \text{hours}$ daily?

Three men $A, B, C$ working together can do a job in $6$ hours less time than $A$ alone,in $1$ hour less time than $B$ alone,and in one-half the time needed by $C$ when working alone. Then $A$ and $B$ together can do the job in (in hours):

$A$ works thrice as good as $B$ and is,therefore,able to finish a piece of work in $60 \text{ days}$ less than $B$. Find the time in which they can complete it,working together (in $\text{days}$).

If $A, B,$ and $C$ can complete a work in $6$ days together. If $A$ can work twice as fast as $B$ and thrice as fast as $C$,then the number of days $C$ alone can complete the work is (in days):