If $3$ men or $5$ women can reap a field in $43$ days,how long will $5$ men and $6$ women take to reap it? (in days)

$A$ can do a work in $20 \, \text{days}$ and $B$ in $40 \, \text{days}$. If they work on it together for $5 \, \text{days}$, then the fraction of the work that is left is:

$A$ and $B$ working separately can do a piece of work in $10 \text{ days}$ and $15 \text{ days}$ respectively. If they work on alternate days beginning with $A$,in how many days will the work be completed?

$A$ 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)

Two workers $A$ and $B$ working together completed a job in $5$ days. If $A$ worked twice as efficiently as he actually did and $B$ worked $1/3$ as efficiently as he actually did,the work would have been completed in $3$ days. To complete the job alone,$A$ would require (in days):

If $28$ men complete $\frac{7}{8}$ of a piece of work in a week,then the number of men,who must be engaged to get the remaining work completed in another week is