In an examination, out of $20$ students in a class, in Mathematics $2$ students scored $100$ marks $, 3$ students scored $0,$ and average marks for rest of the students was $40 .$ What is the average mark of the whole class ? (in $marks$)

The daily maximum temperature in Delhi, for $7$ consecutive days in $May \,1988 ,$ were $42.7^{\circ} C , 44.6^{\circ} C$, $42.0^{\circ} C , 39.1^{\circ} C , 43.0^{\circ} C , 42.5^{\circ} C$ and $38.5^{\circ} C$. Find out the average daily maximum temperature. (in $^{\circ} C$)

The average age of four members of a family is $32\, years.$ If the age of a guest is included, then the average age increased by $12.5 \% .$ What is the age (in $years$) of the guest ?

The average of five consecutive odd integers is $27 .$ What is the product of the first and the last number?

Three $years$ ago the average age of a family of $5$ members was $17\, years.$ With the birth of a new baby, the average remains the same three even today. Find out the age of the baby.(in $years$)

What will be the average of even numbers between $11$ to $63 ?$