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

$A, B, C$ and $D$ are four consecutive even numbers,respectively,and their average is $65$. What is the product of $A$ and $D$?

The average score of Rahul,Manish,and Suresh is $63$. Rahul's score is $15$ less than Ajay and $10$ more than Manish. If Ajay scored $30$ marks more than the average score of Rahul,Manish,and Suresh,what is the sum of Manish's and Suresh's scores?

The average salary per head of all workers of an institution is $Rs. 60$. The average salary per head of $12$ officers is $Rs. 400$. The average salary per head of the rest is $Rs. 56$. Then,the total number of workers in the institution is?

The average of the first nine prime numbers is

The average of $17$ numbers is $10.9$. If the average of the first $9$ numbers is $10.5$ and the average of the last $9$ numbers is $11.4$, find the middle number.