$A$ library has an average of $510$ visitors on Sundays and $240$ on other days. The average number of visitors per day in a month of $30$ days beginning with a Sunday is:

The average age of a husband,wife,and their child $3 \text{ years}$ ago was $27 \text{ years}$,and the average age of the wife and the child $5 \text{ years}$ ago was $20 \text{ years}$. The present age of the husband is (in $\text{years}$):

$19$ persons went to a hotel for a combined dinner party. $13$ of them spent $Rs. 79$ each on their dinner and the rest spent $Rs. 4$ more than the average expenditure of all the $19$ persons. What was the total money spent by them?

The average weight of $3$ persons is $65 \, kg$. If a fourth person having a weight of $45 \, kg$ joins the group,what is the average weight of the group? (in $kg$)

The average temperature for Monday,Tuesday,Wednesday and Thursday was $48^{\circ}$. The average temperature for Tuesday,Wednesday,Thursday and Friday was $52^{\circ}$. If the temperature on Monday was $42^{\circ}$,then the temperature on Friday was (in $degrees$):

The average age of $10$ men is increased by $2 \, \text{years}$ when one of them, aged $25 \, \text{years}$, is replaced by a new man. What is the age of the new man (in $\text{years}$)?