$A, B$ 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 $min$)

$A$ does $\frac{4}{5}$ of a work in $20 \, \text{days}$. He then calls in $B$ and they together finish the remaining work in $3 \, \text{days}$. How long would $B$ alone take to do the whole work? (in $\text{days}$)

If $6$ men and $8$ boys can do a piece of work in $10$ days and $26$ men and $48$ boys can do the same work in $2$ days,the time taken by $15$ men and $20$ boys to do the same type of work will be (in days)

If $6$ men and $8$ boys can do a piece of work in $10$ $days$ while $26$ men and $48$ boys can do the same in $2$ $days,$ the time taken by $15$ men and $20$ boys in doing the same type of work will be (in $days$)

$A$ man can do a work in $10\, days$. With the help of a boy,he can do the same work in $6\, days$. If they get $Rs.\, 50$ for that work,what is the share of that boy? (in $Rs.$)

$A$ and $B$ can do a piece of work in $12$ days and $15$ days,respectively. They began to work together,but $A$ left after $4$ days. In how many more days would $B$ alone complete the remaining work?