$A$ and $B$ can do a piece of work in $18$ days,$B$ and $C$ in $24$ days,and $A$ and $C$ in $36$ days. In what time can they do it all working together? (in days)

$A$ is twice as good a workman as $B$. Working together,they finish a piece of work in $1.5$ days. $A$ alone can finish the work in (in days):

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)

$A$ and $B$ together can do a piece of work in $9$ days. If $A$ does thrice the work of $B$ in a given time,the time $A$ alone will take to finish the work is (in days)

$A, B$ and $C$ can do a piece of work individually in $8, 10$ and $15$ days respectively. $A$ and $B$ start working,but $A$ quits after working for $2$ days. After this,$C$ joins $B$ until the completion of the work. In how many days will the work be completed?

$x$ number of men can finish a piece of work in $30$ days. If there were $6$ men more,the work could be finished in $10$ days less. The actual number of men is