$A$ club has $15$ men and $25$ women. The average age of men is $10 \text{ years}$ and the average age of women is $12 \text{ years}$. What is the average age of the whole club in years?

The cost of $5 \,kg$ of apples is $Rs. \, 450$. The cost of $12$ dozen mangoes is $Rs. \, 4320$,and the cost of $4 \,kg$ of oranges is $Rs. \, 240$. What is the total cost of $8 \,kg$ of apples,$8$ dozen mangoes,and $8 \,kg$ of oranges? (in $Rs.$)

What is the average of the squares of the first $19$ natural numbers?

In a competitive examination,the average marks obtained was $45$. It was later discovered that there was some error in computerization and the marks of $90$ candidates had to be changed from $80$ to $50$,and the average came down to $40$ marks. The total number of candidates appeared in the examination is

$3 \, \text{years}$ ago,the average age of a family of $5 \, \text{members}$ was $17 \, \text{years}$. With the birth of a new baby,the average age of the $6 \, \text{members}$ remains the same even today. Find the age of the new baby in years.

The average of the first $7$ integers in a series of $13$ consecutive odd integers is $37$. What is the average of the entire series?