Direction : What value should come in the place of question mark (?) in the following questions?

$$ \sqrt{1089} + 3=(?)^2 $$

Study the following table carefully and answer the questions given below.

What was approximate percentage increase in the number of students in Commerce discipline from 2003 to 2004?

The length, breadth and height of a room is 21 metres, 12 metres and 16 metres. What will be the length of the largest rod that can be placed in that room?

Given k = -3. Find the value of $$ {k^3+3k}$$. 

Two numbers are 90 % and 75 % lesser than a third number. By what % should the first number be increased so that it becomes equal to the second number? 

When 3738, 5659 and 9501 are divided by the greatest possible number x, the remainder in each case is y. What is the sum of x and y?

In 16 minutes, the minute had gains over the hour hand by

What should come at place of question mark (?) in the following number series?

15 20 50 165 680 ?