Kamal can do a work in $15$ days. Sita is $50$ percent more efficient than Kamal in doing the work. In how many days will Sita do that work?

$A$ and $B$ can do a job alone in $12 \text{ days}$ and $15 \text{ days}$ respectively. $A$ starts the work and after $6 \text{ days}$,$B$ also joins to finish the work together. For how many days did $B$ actually work on the job?

$A$ alone can complete a work in $16$ days and $B$ alone in $12$ days. Starting with $A$,they work on alternate days. The total work will be completed in (in days):

$A, B$ and $C$ together earn $Rs. 2700$ in $18$ days. $A$ and $C$ together earn $Rs. 940$ in $10$ days. $B$ and $C$ together earn $Rs. 1520$ in $20$ days. Find the daily earning of $C$ (in $Rs.$).

$A, B$ and $C$ together can complete a piece of work in $30\, min$. $A$ and $B$ together can complete the same work in $50\, min$. $C$ alone can complete the work in? (in $min$)

$A$ can do a piece of work in $120$ days and $B$ can do it in $150$ days. They work together for $20$ days. Then $B$ leaves and $A$ alone continues the work. After $12$ days,$C$ joins $A$ and the work is completed in $48$ days more. In how many days can $C$ do it if he works alone?