$4$ men and $6$ women can complete a work in $8$ days,while $3$ men and $7$ women can complete it in $10$ days. In how many days will $10$ women complete it?

$A$ can do a work in $20 \, \text{days}$ and $B$ in $40 \, \text{days}$. If they work on it together for $5 \, \text{days}$, then the fraction of the work that is left is:

$A$ can complete a piece of work in $40$ days. He starts working,but having some other engagements,he leaves after $5$ days. Thereafter,$B$ completes the remaining work in $21$ days. How many days would $A$ and $B$ take to complete this work working together?

$P, Q$ and $R$ undertake to do a work for $Rs. 660$. $P$ and $Q$ together do $8/11$ of the work and the rest is done by $R$ alone. How much should $R$ get? (in $Rs.$)

$A$ man is twice as fast as a woman and a woman is twice as fast as a boy in doing a work. If all of them, a man, a woman and a boy, can finish the work in $7$ days, in how many days will a boy do it alone?

$A$ 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):