$A$ and $B$ together can complete a work in $12$ days. $A$ alone can complete it in $20$ days. If $B$ does the work only for half a day daily,then in how many days will $A$ and $B$ together complete the work?

$B$ would have taken $10 \, \text{hours}$ more than what $A$ would have taken to complete a task if each of them worked alone. Working together they can complete the task in $12 \, \text{hours}$. How many $\text{hours}$ would $B$ take to do $50 \%$ of the task?

If a job is to be completed in $10 \, \text{days}$,it requires $270 \, \text{persons}$. If $180 \, \text{persons}$ take up the same job,they will finish it in (in $\text{days}$):

Nikita,Nishita,and Kavita can complete a work in $2 \frac{2}{3}$ days. If Nishita and Kavita can complete it in $4$ days,and Nishita alone can do it in $6$ days,then in how many days can Nikita and Nishita complete the work?

$3$ men and $4$ boys can complete a certain work in $8$ days,while $4$ men and $4$ boys can complete the same work in $6$ days. Then $2$ men and $4$ boys will finish it in ........ days.

$15$ men take $20$ days to complete a job working $8$ hours a day. How many hours a day should $20$ men work to complete the same job in $12$ days?