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

125% of 2440 – 75% of 1856 = ?

What is the value of X ?, if 7580 - X = 3440

If 551 ÷ 29 = 19 then 5.51 ÷ 0.0019 = ?

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

What is the value of $${0.74×1.23×0.13\over (0.37)^{3}+(0.41)^{3}-8(0.39)^{3}}$$ ?

The smallest 4- digit number which is a perfect square is 

The value of $$ \sqrt{11.981+7\sqrt{1.2996}}$$ is closest to 

A bag has Rs.420 in the denomination of Rs.1, Rs. 2 and Rs. 5 coins. The number Rs.1, Rs.2 and Rs.5 coins are in the ratio of 8: 1:5. How many coins of Rs.5 are in the bag?