The average age of a group of $9$ students is $20\, \text{years}$. When $6$ more students joined the group,the average age falls by $2\, \text{years}$. The average age of the new students is:

The average of $6$ numbers is $3.95$. The average of two of them is $3.4$,while the average of the other two is $3.85$. What is the average of the remaining two numbers?

The average of $30$ numbers is $12$. The average of the first $20$ of them is $11$ and that of the next $9$ is $10$. The last number is:

Of three numbers,the second is thrice the first and the third number is three-fourths of the first. If the average of the three numbers is $114$,the largest number is

The average age of a board of directors of a company,having $10$ directors,was $48$ years. Coincidentally,when a director aged $53$ resigned from the board,another director died on the same day. $A$ new director aged $34$ joined the board. Next year in the same month,the average age of all the $9$ directors was found to be $46$ years. The age of the late (i.e.,dead) director at the time of his death was (in years):

The average temperature from Monday to Thursday is $48^{\circ} C$ and from Tuesday to Friday,the average temperature is $52^{\circ} C$. If the temperature on Monday is $42^{\circ} C$,what was the temperature on Friday in $^{\circ} C$?