$A$ and $B$ can complete a piece of work in $8$ days,$B$ and $C$ can do it in $12$ days,and $C$ and $A$ can do it in $8$ days. In how many days can $A, B,$ and $C$ together complete the work?

Rohan and Mohit can build a wall in $8 \, days$,Mohit and Vikas can build the same wall in $10 \, days$,and Vikas and Rohan can build the same in $12 \, days$. In how many days can all three complete the same wall while working together?

The work done by a woman in $8\, \text{hours}$ is equal to the work done by a man in $6\, \text{hours}$ and by a boy in $12\, \text{hours}$. If working $6\, \text{hours per day}$,$9$ men can complete a work in $6\, \text{days}$,then in how many $\text{days}$ can $12$ men,$12$ women,and $12$ boys together finish the same work working $8\, \text{hours per day}$?

If $8$ men or $10$ women can do a piece of work in $50$ days,in what time will $28$ men and $15$ women do it? (in days)

$12$ 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?

$A$ and $B$ can together finish a work in $30$ days. They worked at it for $20$ days and then $B$ left. The remaining work was done by $A$ alone in $20$ more days. $A$ alone can finish the work in (in days):