$19$ 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 of $100$ observations was calculated as $35$. It was found later that one of the observations was misread as $83$ instead of $53$. The correct average is: (in $.7$)

What is the average of all numbers between $8$ and $74$ which are divisible by $7\, ?$

The average age of a class of $30$ students and a teacher reduces by $0.5 \, \text{years}$ if we exclude the teacher. If the initial average is $14 \, \text{years}$,find the age of the class teacher in $\text{years}$.

$A$ man spends on an average $Rs. 269.47$ for the first $7$ months and $Rs. 281.05$ for the next $5$ months. Find out his monthly salary if he saved $Rs. 308.46$ during the year. (in $Rs.$)

Mr. Patel walked $6 \, km$ to reach the station from his house,then he boarded a train whose average speed was $60 \, km/hr$ and thus he reached his destination. In this way,he took a total of $3 \, hours$. If the average speed of the entire journey was $32 \, km/hr$,then the average speed of walking is (in $km/hr$):