$45$ men complete a piece of work in $30$ days working $12$ hours a day. In how many days will $60$ men complete the work working $10$ hours a day?

$12$ men can complete a piece of work in $4$ days,while $15$ women can complete the same work in $4$ days. $6$ men start working on the job and after working for $2$ days,all of them stopped working. How many women should be put on the job to complete the remaining work,if it is to be completed in $3$ days?

$A$ 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 $Rs.$)

$P, Q$ and $R$ can finish a work in $10, 12$ and $15$ days respectively. If $Q$ stops after $2$ days,how long would it take $P$ and $R$ to finish the remaining work? (in days)

$P$ and $Q$ complete a certain work in $30 \, days$,$Q$ and $R$ in $40 \, days$,while $R$ and $P$ in $60 \, days$. How long will they take to finish it together? (in $days$)

If $6$ men and $8$ boys can do a piece of work in $10$ $days$ while $26$ men and $48$ boys can do the same in $2$ $days,$ the time taken by $15$ men and $20$ boys in doing the same type of work will be (in $days$)