If the average of $6$ consecutive even numbers is $25 ,$ the difference between the largest and the smallest number is

The average weight of $15$ oarsmen in a boat is increased by $1.6\, kg$ when one of the crew, who weighs $42\, kg$ is replaced by a new man. Find the weight of the new man (in $kg$)

In a class, there are $20$ boys whose average age is decreased by $2$ $months,$ when one boy aged $18\, years$ in replaced by a new boy. The age of the new boy is

Of the three numbers, the average of the first and the second is greater than the average of the second and the third by $15 .$ What is the difference between the first and the third of the three numbers?

Out of $30$ teachers of a school, a teacher of age $60$ $years$ retired. In his place another teacher of age $30$ $years$ was appointed. As a result, the mean age of the teachers will

The average of three numbers of which greatest is $16$ is $12 .$ If the smallest is half of the greatest the remaining number is