The average of first nine prime numbers is
$9$
$11$
$11 \frac{2}{9}$
$11 \frac{1}{9}$
The mean of $11$ numbers is $35 .$ If the mean of first $6$ numbers is $32$ and that of the last $6$ numbers is $37,$ then find the sixth number.
The average salary of all the workers in a workshop is $Rs.\,8000.$ The average salary of $7$ technicians is $Rs.\, 12000$ and the average salary of the rest is $Rs.\,6000 .$ The total number of workers in the workshop 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
The average of $50$ numbers is $38 .$ If two numbers $45$ and $55$ are discarded, the average of the remaining set of numbers is
After replacing an old member by a new member, it was found that the average age of five members of a club is the same assit was $3 \,year$ ago. The difference between the ages of the replaced and the new member is ? (in $year$)