3. Two marks example problems I

1. $A$ and $B$ together can do a piece of work in $16$ days and $A$ alone can do it in $48$ days. How long will $B$ take to complete the work?

 

Number of days $=$

 

 

2. $A$ works $3$ times as fast as $B$ and is able to complete a work in $24$ days less than the days taken by $B$. Find the time in which they can complete the work together.

 

Number of days $=$