$A$ is twice as good a workman as $B$ and together they finish a piece of work in $14$ days. The number of days taken by $A$ alone to finish the work is (in days):

$A, B$ and $C$ can complete a piece of work in $6, 12$ and $24$ days respectively. They altogether will complete the work in (in days):

$P$ can complete a work in $12$ days working $8$ hours a day. $Q$ can complete the same work in $8$ days working $10$ hours a day. If both $P$ and $Q$ work together,working $8$ hours a day,in how many days can they complete the work?

Kamal can do a work in $15$ days. Sita is $50$ percent more efficient than Kamal in doing the work. In how many days will Sita do that work?

$A$ contractor has the target of completing a work in $40 \text{ days}$. He employed $20$ persons who completed $\frac{1}{4}$ of the work in $10 \text{ days}$ and left. The number of additional persons he has to employ to finish the remaining part of the work as per the target is:

Sixteen men can complete a work in $15$ days,$24$ children can do the same work in $20$ days. In how many days will $8$ men and $8$ children complete the same work?