$A$ contractor has the target of completing a work in $40 \text{ days}$. He employed $20$ persons who completed $\frac{1}{4}$ of the work in $10 \text{ days}$ and left. The number of additional persons he has to employ to finish the remaining part of the work as per the target is:

Sakshi can do a piece of work in $20$ days. Tanya is $25\%$ more efficient than Sakshi. The number of days taken by Tanya to do the same piece of work is

$A$ can do a piece of work in $30$ days while $B$ can do it in $40$ days. In how many days can $A$ and $B$ working together do it?

$A$ alone would take $27 \, \text{days}$ more to complete the job than if both $A$ and $B$ worked together. If $B$ worked alone, he would take $3 \, \text{days}$ more to complete the job than $A$ and $B$ working together. What time would they take if both $A$ and $B$ worked together? (in $\text{days}$)

$A$'s $2$ days work is equal to $B$'s $3$ days work. If $A$ can complete the work in $8$ days,then to complete the work $B$ will take (in days):

$A$ can do a work in $12 \, days$. When he had worked for $3 \, days$,$B$ joined him. If they complete the work in $3$ more $days$,in how many $days$ can $B$ alone finish the work?