If the sum and difference of two number are 20 and 8 respectively, then the difference of their squares is: 

The smallest positive integer when multiplied by 392, the product is a perfect square, is 

The simplified value of
$${{1\over 3}÷{1\over 3}×{1\over 3}\over{1\over 3}÷{1\over 3}of{1\over 3}}-{1\over 9}$$

The value of $${\sqrt{40+\sqrt{9\sqrt{81}}} }$$ is

Which smallest number must be added to 2203 so that we get a perfect square? 

Direction : What should come in place of the question (?) in the following question.

140% of 450 + 24% of 650 =?

The number, whose square is equal to the difference between the squares of 975 and 585, is: