The average weight of $8$ sailors in a boat is increased by $1 \, kg$ if one of them weighing $56 \, kg$ is replaced by a new sailor. The weight of the new sailor is (in $kg$):

With an average speed of $40 \, km/h$,a train reaches its destination on time. If it goes with an average speed of $35 \, km/h$,it reaches late by $15 \, \text{minutes}$. The total journey is (in $km$):

The average of four consecutive odd numbers is $40$. What is the largest number?

The average of two numbers $A$ and $B$ is $20,$ that of $B$ and $C$ is $19,$ and that of $C$ and $A$ is $21.$ What is the value of $A?$

David obtained $76, 65, 82, 67$ and $85$ marks (out of $100$) in English,Mathematics,Physics,Chemistry,and Biology. What is his average marks?

The mean of marks secured by $50$ students in division $A$ of class $X$ is $61$,$25$ students of division $B$ is $57$,and that of $50$ students of division $C$ is $55$. What will be the mean of marks of the students of three divisions of Class $X$?