If 0.5x + 0.7y=0.5 and 0.7x + 0.5y=0.7,then the value of x+y is

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

(41) ² + (38)² × (0.15)²=?

If $${4x^2={15^2-9^2}}$$ then the value of x is

How many perfect squares lie between 120 and 300? 

Simplify the following equation.
$${(785.785.785+435.435.435) \over(785)^{2}+(435)^{2}-(785)(435)}$$

23+ 3+33+333+3.33=?

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

(?)² + (65)²=(160)² -  (90)² – 7191

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