Of the three numbers,the first is twice the second and the second is thrice the third. If the average of the three numbers is $10$,the numbers are

What is the age of a class teacher?
$I.$ There are $11$ students in the class.
$II.$ The average age of the students and the teacher is $14$ years.
$III.$ The average age of the teacher and the students is $3$ years more than that of the students.

The average salary per head of all the workers in a company is $Rs. \,95$. The average salary of $15$ officers is $Rs. \,525$ and the average salary per head of the rest is $Rs. \,85$. Find the total number of workers in the workshop.

The daily earnings of a taxi driver during a week are: $Rs. 60, Rs. 65, Rs. 70, Rs. 52.50, Rs. 63, Rs. 73,$ and $Rs. 68$. What is his average daily earning for the week (in $.50$)? (in $Rs.$)

The average of six numbers is $32$. If each of the first three numbers is increased by $2$ and each of the remaining three numbers is decreased by $4$,then the new average is?

Out of four numbers,whose average is $60$,the first one is one-fourth of the sum of the last three. The first number is