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

The average weight of $25$ persons is increased by $1 \, kg$ when one man weighing $60 \, kg$ is replaced by a new person. What is the weight of the new person (in $kg$)?

In an examination,the average marks obtained by the girls of a class is $85$ and the average marks obtained by the boys of the same class is $87$. If the girls and boys are in the ratio $4:5$,the average marks of the whole class (approx.) is closest to:

The average of a collection of $20$ measurements was calculated to be $56 \, cm$. But later,it was found that a mistake had occurred in one of the measurements which was recorded as $64 \, cm$,but should have been $61 \, cm$. The correct average must be? (in $cm$)

The average of $30$ numbers is $15$. The average of the first $18$ numbers is $10$ and that of the next $11$ numbers is $20$. The last number is:

Average age of $15$ students of a class is $15 \text{ years}$. Out of these,the average age of $5$ students is $14 \text{ years}$ and that of the other $9$ students is $16 \text{ years}$. The age of the $15^{th}$ student is (in $\text{years}$):