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?

The average age of a group of $18$ persons is $32$ $years$ and $6$ $months$. If two persons of age $65$ $years$ each and one person of age $50$ $years$ leave the group,the average age of the remaining persons in the group will be (in $years$)

The average monthly income of $P$ and $Q$ is $Rs. 5050$. The average monthly income of $Q$ and $R$ is $Rs. 6250$ and the average monthly income of $P$ and $R$ is $Rs. 5200$. The monthly income of $P$ is

The sum of three numbers is $98$. If the ratio between the first and second is $2:3$ and that between the second and the third is $5:8$,then the second number is

The average of the first $100$ positive integers is

The average marks in English subject of a class of $24$ students is $56$. If the marks of three students were misread as $44, 45$ and $61$ instead of the actual marks $48, 59$ and $67$ respectively,then what would be the correct average?