$A$ man travels by a car to his office at $60 \, km/h$ and returns home along the same route at $20 \, km/h$. Find the average speed of his whole journey (in $km/h$).

In a school, the average age of students is $6 \, \text{years}$, and the average age of $12$ teachers is $40 \, \text{years}$. If the average age of the combined group of all the teachers and students is $7 \, \text{years}$, then the number of students is?

$A$ 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

Fifteen movie theatres average $600$ customers per theatre per day. If $six$ of the theatres close down but the total theatre attendance stays the same,then the average daily attendance per theatre among the remaining theatres is:

Refer to the line graph and answer the given question.
Number of candidates who qualified in a given competitive examination from $6$ states during two given years.
What is the average number of candidates who qualified in the given competitive exam from states $Q, S, T$ and $U$ in $2004$?

The average monthly expenditure of a family for the first four months is $Rs. 2750$,for the next three months is $Rs. 2940$,and for the last five months is $Rs. 3130$. If the family saves $Rs. 5330$ throughout the year,find the average monthly income of the family for that year (in $Rs.$).