$2$ men and $3$ boys can do a piece of work in $10$ days, while $3$ men and $2$ boys can do the same work in $8$ days. In how many days can $2$ men and $1$ boy do the work?

If $3$ men or $4$ women can reap a field in $43$ days, then the number of days in which the field can be reaped by $7$ men and $5$ women is:

$8$ taps having the same rate of flow can fill a tank in $27$ min. If two taps go out of order, then the time taken by the remaining taps of fill the tank will be:

On tap can fill a tank in one hour, while the other can empty it in fifty min. If the tank is full and both the taps are opened, what time will the tank be emptied?

A tank can be filled by one tap in $20$ min and by another in $25$ min. Both the taps are kept open for $5$ min and then the second tap is turned off. In how many minutes more is the tank completely filled?

Pipe A and B running together can fill a cistern in $6$ min. If B takes $5$ min more than A to fill the cistern, then the times in which A and B will fill the cistern separately will be respectively:

Two pipes A and B can fill a tank in $36$ min and $45$ min respectively. Another pipe C can empty the tank in $30$ min. First A and B are opened. After $7$ min, C is also opened. The tank is filled up in:

Three taps A, B and C fill a tank in$20$ min, $15$ min and $12$ min respectively. If all the taps are opened simultaneously, how long will they take to fill $40\%$ of the tank?