$P, Q$ 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 $Rs.$)

$A$ 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?

$A$ does a work in $10$ $days$ and $B$ does the same work in $15$ $days$. In how many $days$ will they together do the same work?

If a work can be completed by $A$ in $30 \text{ days}$ and by $B$ in $60 \text{ days}$,then the number of days taken by them to finish the work,working together,is

$A$ man and a boy received $Rs. 800$ as wages for $5$ days for the work they did together. The man's efficiency in the work was three times that of the boy. What are the daily wages of the boy? (in $Rs.$)

$5$ men can prepare $10$ toys in $6$ days working $6$ hours a day. Then,in how many days can $12$ men prepare $16$ toys working $8$ hours a day? (in days)