What is the average of all numbers between $100$ and $200$ which are divisible by $13$ (in $.5$)?

$A$ cricketer,whose bowling average was $12.4$ runs/wicket,takes $5$ wickets for $22$ runs in a match,thereby decreasing his average by $0.4$. The number of wickets taken by him before this match was:

Out of nine persons,eight persons spent $Rs. \,30$ each for their meals. The ninth person spent $Rs. \,20$ more than the average expenditure of all the nine persons. What was the total money spent by all of them (in $Rs.$)?

If the mean of $5$ observations $x, x+2, x+4, x+6$ and $x+8$ is $11,$ then the mean of the last three observations is

Three years ago,the average age of a family of $5$ members was $27 \, \text{years}$. The present average age is also $27 \, \text{years}$ after the inclusion of a child into the family. Find the age of the child in years.

The average of $6$ numbers is $20$. If one number is removed, the average becomes $15$. What is the number removed?