Visitors to a show were charged $Rs. 15.00$ each on the first day,$Rs. 7.50$ on the second,and $Rs. 2.50$ on the third day. The total attendance of visitors for the three days was in the ratio $2:5:13$. Find the average charge per visitor for the entire show (in $Rs.$).

The average monthly salary of a staff of $9$ persons is $Rs.\, 2450$. One member of the staff whose monthly salary is $Rs.\, 2650$ is transferred. Find out the average salary of the remaining $8$ persons of the staff (in $Rs.$).

The average weight of all the $11$ players of the Indian cricket team is $50 \, kg$. If the average weight of the first six lightest players is $49 \, kg$ and that of the six heaviest players is $52 \, kg$,find the weight of the player who is in the sixth position when all $11$ players are arranged in order of increasing weights (in $kg$).

The average age of four brothers is $12 \, \text{years}$. If the age of their mother is also included, the average increases by $5 \, \text{years}$. The age of the mother (in $\text{years}$) is:

The average of $50$ numbers is $38$. If two numbers,namely,$45$ and $55$ are discarded,what is the average of the remaining numbers (in $.5$)?

Amitabh's average expenditure from $January$ to $June$ is $Rs. 4200$. He spends $Rs. 1200$ in $January$ and $Rs. 1500$ in $July$. What is the average expenditure for the months of $February$ to $July$ (in $Rs.$)?