What is the value of $$ {0.55 × 4.5\over 0.81}$$ ?

If  $$\sqrt{2}=1.414$$, the value of $${ \sqrt{2}-1\over\sqrt{2}+1}$$  is nearest to 

On simplification of   $$ {(2.664)^2-(2.356)^2\over0.288}$$

The smallest number that must be subtracted from 1000 to make the resulting number a perfect square is 

Evaluate: $${-(4-6)^2-3(-2)+।-6।\over 18-9÷3×5}$$

Simplify  $$ ^{3}\sqrt{-2197} × ^{3}\sqrt{{-125}} \ ÷ ^{3}\sqrt{27\over512}$$.

  $$25\% \ of (50\% \ of \ 30\% \ of \ 150)\over 40\% of \ 2250$$ is equal to:

25.6% of 250 +√ ? = 119