$A, B$ and $C$ together can finish a piece of work in $4$ days. $A$ alone can do it in $12$ days and $B$ alone in $18$ days. How many days will be taken by $C$ to do it alone?

$45$ men can complete a work in $16$ days. Four days after they started working,$36$ more men joined them. How many days will they now take to complete the remaining work?

$A$ and $B$ can do a job alone in $12 \text{ days}$ and $15 \text{ days}$ respectively. $A$ starts the work and after $6 \text{ days}$,$B$ also joins to finish the work together. For how many days did $B$ actually work on the job?

To complete a work,$A$ takes $50 \%$ more time than $B$. If together they take $18 \text{ days}$ to complete the work,how much time shall $B$ take to do it? (in days)

$5$ men can complete a work in $2$ days,$4$ women can complete the same work in $3$ days and $5$ children can do it in $3$ days. $1$ man,$1$ woman and $1$ child,working together,can complete the work in (in days):

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 $8\, \text{hours per day}$?