The mean marks of $10$ boys in a class is $70 \%$,whereas the mean marks of $15$ girls is $60 \%$. The mean marks of all the $25$ students is

$A$ team of $8$ persons participates in a shooting competition. If the best marksman had scored $92$ points instead of $85$ points, the average score for the team would have been $84$. What was the total number of points the team actually scored?

The mean of $100$ items was $46$. Later on,it was discovered that an item $16$ was misread as $61$ and another item $43$ was misread as $34$. It was also found that the number of items was $90$ and not $100$. What is the correct mean?

Out of $9$ persons,$8$ persons spent $Rs. 30$ each for their meals. The ninth one spent $Rs. 20$ more than the average expenditure of all the nine. The total money spent by all of them was (in $Rs.$)

The average age of $5$ members is $21 \text{ years}$. If the age of the youngest member is $5 \text{ years}$,find out the average age of the family at the birth of the youngest member (in $\text{years}$).

The average earning of a mechanic for the first four days of a week is $Rs. 18$ and for the last four days is $Rs. 22$. If he earns $Rs. 20$ on the fourth day,his average earning for the whole week is (in $Rs.$)