The average of $50$ numbers is $38 .$ If two numbers $45$ and $55$ are discarded, the average of the remaining set of numbers is

In a school with $600$ students, the average age of the boys is $12$ $years$ and that of the girls is $11\, years.$ If the average age of the school is $11 \,years$ and $9 \,months,$ then the number of girls in the school is

The average age of students of a class is $15.8 \,years.$ The average age of boys in the class is $16.4$ $years$ and that of the girls is $15.4\, years.$ The ratio of number of boys to the number of girls in the class is:

If the average of $m$ numbers is $n^{2}$ and that of $n$ numbers is $m^{2},$ then the average of $( m + n )$ numbers is

The average age of a group of $15$ students is $10 \,years.$ When $5$ more students joined the group, the average got increased by $1\, year.$ The age of the new student is (in $years$)

The sum of five consecutive integers is $a$ and the sum of next five consecutive integers is $b$. Then $\frac{(b-a)}{100}$ is equal to