Two men can do a piece of work in $x$ days. But $y$ women can do it in $3$ days. Then the ratio of the work done by $1$ man and $1$ woman is

$A$ can do a certain work in the same time in which $B$ and $C$ together can do it. If $A$ and $B$ together could do it in $10 \text{ days}$ and $C$ alone in $50 \text{ days}$,then $B$ alone could do it in (in $\text{days}$):

$A$ can do a work in $12$ days. When he had worked for $3$ days,$B$ joined him. If they complete the work in $3$ more days,in how many days can $B$ alone finish the work?

$P, Q$ and $R$ undertake to do a work for $Rs. 707$. $P$ and $Q$ together do $\frac{5}{7}$ of the work and the rest is done by $R$ alone. How much should $R$ get? (in $Rs.$)

$20$ men can complete a piece of work in $16$ days. After $5$ days from the start of the work,some men left. If the remaining work was completed by the remaining men in $18 \frac{1}{3}$ days,how many men left after $5$ days from the start of the work?

$A$ and $B$ can together finish a work in $30$ days. They worked together for $20$ days and then $B$ left. After another $20$ days,$A$ finished the remaining work. In how many days can $A$ alone finish the job?