$A$ can do a piece of work in $4\, h$,$B$ and $C$ can do it in $3\, h$,and $A$ and $C$ can do it in $2\, h$. How long will $B$ alone take to do it? (in $h$)

$A$ and $B$ can together complete a task in $18$ hours. After $6$ hours, $A$ leaves. $B$ takes $36$ hours to finish the rest of the task. How many hours would $A$ have taken to do the task if he worked alone?

$A$ and $B$ working separately can do a piece of work in $9$ and $12$ days,respectively. If they work for a day alternately with $A$ beginning,the work would be completed in (in days):

$3$ men and $4$ boys can complete a certain work in $8$ days,while $4$ men and $4$ boys can complete the same work in $6$ days. Then $2$ men and $4$ boys will finish it in ........ days.

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

$4$ girls can complete a piece of work in $8$ days,the same work $3$ boys can complete in $9$ days,$7$ men in $2$ days,and $5$ women in $4$ days. Who among them has the minimum capacity of work?