$A$ alone can complete a work in $18 \, days$ and $B$ alone in $15 \, days.$ $B$ alone worked at it for $10 \, days$ and then left the work. In how many more days will $A$ alone complete the remaining work?

Two women,Sita and Gita,working separately can mow a field in $8$ and $12 \, hrs$ respectively. If they work in stretches of one hour alternatively,with Sita beginning at $9:00 \, a.m.$,when will the mowing be finished? (in $p.m.$)

Two workers $A$ and $B$ working together completed a job in $5$ days. If $A$ worked twice as efficiently as he actually did and $B$ worked $1/3$ as efficiently as he actually did,the work would have been completed in $3$ days. To complete the job alone,$A$ would require (in days):

Two workers $A$ and $B$ working together completed a job in $5$ days. If $A$ worked twice as efficiently as he actually did and $B$ worked $\frac{1}{3}$ as efficiently as he actually did,the work would have completed in $3$ days. Find the time for $A$ to complete the job alone (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 $days$)

$10$ men can finish a piece of work in $10$ days,whereas it takes $12$ women to finish it in $10$ days. If $15$ men and $6$ women undertake to complete the work,how many days will they take to complete it?