$4$ men and $6$ women earn $Rs. \, 1600$ by doing a piece of work in $5$ days. $3$ men and $7$ women earn $Rs. \, 1740$ by doing the same work in $6$ days. In how many days can $7$ men and $6$ women complete the same work while earning $Rs. \, 3760$?

$60$ men could complete a work in $250$ days. They worked together for $200$ days. After that,the work had to be stopped for $10$ days due to bad weather. How many more men should be engaged to complete the work on time?

$A$ can do a piece of work in $12$ days and $B$ in $15$ days. They work together for $5$ days and then $B$ leaves. The number of days taken by $A$ to finish the remaining work is:

Two men can do a piece of work in $x$ days. But $y$ women can do it in $3$ days. Then the ratio of the work done by $1$ man and $1$ woman is

$A$ 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?

$A$ tyre has two punctures. The first puncture alone would have made the tyre flat in $9 \,minutes$ and the second alone would have done it in $6 \,minutes.$ If air leaks out at a constant rate,how long does it take both the punctures together to make it flat? (in $minutes$)