Shashi can do a piece of work in $20$ days. Tanya is $25\%$ more efficient than Shashi. The number of days taken by Tanya to do the same piece of work is

One man,$3$ women,and $4$ boys can do a work in $96$ hours,$2$ men and $8$ boys can do it in $80$ hours,and $2$ men and $3$ women can do it in $120$ hours. In how many hours can it be done by $5$ men and $12$ boys? (in hours)

Two women,Sita and Gita,working separately can mow a field in $8$ and $12 \, hrs$ respectively. If they work in stretches of one hour alternatively,with Sita beginning at $9:00 \, a.m.$,when will the mowing be finished? (in $p.m.$)

$A$ can finish a work in $24$ days,$B$ in $9$ days and $C$ in $12$ days. $B$ and $C$ start the work but are forced to leave after $3$ days. The remaining work was done by $A$ in (in days):

$7$ men can complete a piece of work in $12$ days. How many additional men will be required to complete double the work in $8$ days?

Two men undertake a piece of work for $Rs. 600$. Individually,they can complete the work in $6$ days and $8$ days,respectively. With the assistance of a boy,they completed the work in $3$ days. The boy's share should be (in $Rs.$)