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

The average of $6$ numbers is $8$. What is the $7^{th}$ number so that the average becomes $10$?

The arithmetic mean of the scores of a group of students in a test was $52$. The brightest $20\%$ of them secured a mean score of $80$ and the dullest $25\%$ a mean score of $31$. The mean score of the remaining $55\%$ is

Out of $9$ persons,$8$ persons spent $Rs. 30$ each for their meals. The ninth one spent $Rs. 20$ more than the average expenditure of all the nine. The total money spent by all of them was (in $Rs.$)

$10 \, kg$ of rice priced at $Rs. \, 12$ per $kg$ is mixed with $6 \, kg$ of rice priced at $Rs. \, 16$ per $kg$. Find the average price in $Rs.$ per $kg$ of the whole mixture?

$A$ cricketer has a certain average for $10$ innings. In the eleventh inning,he scored $108$ runs,thereby increasing his average by $6$ runs. His new average is