$A$ and $B$ can separately complete a piece of work in $20$ days and $30$ days respectively. They worked together for some time,then $B$ left the work. If $A$ completed the rest of the work in $10$ days,then for how many days did $B$ work?

$A$ alone can do a piece of work in $6$ days and $B$ alone in $8$ days. $A$ and $B$ undertook to do it for $Rs. 3200$. With the help of $C$,they completed the work in $3$ days. How much is to be paid to $C$ (in $Rs.$)?

Ram can finish a work in $15 \text{ days}$ working $8 \text{ hrs/day}$. Fari can finish it in $6 \frac{2}{3} \text{ days}$ at $9 \text{ hrs/day}$. Find in how many days both can finish it together,if both work $10 \text{ hrs/day}$?

The total number of men,women,and children working in a factory is $18$. They earn $Rs. 4000$ in a day. If the sum of the wages of all men,all women,and all children is in the ratio $18: 10: 12$,and the wages of an individual man,woman,and child are in the ratio $6: 5: 3$,then how much does a woman earn in a day? (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)

$A$ and $B$ together can do a piece of work in $10$ days. $A$ alone can do it in $30$ days. The time in which $B$ alone can do it is (in days):