$$ \sqrt{.081×.484\over0.0064×6.25}=?$$

If $$ \sqrt{0.04×0.4×a} =0.4×0.04×{\sqrt{b}}$$ then the value of $$ {a\over b}$$ is:

The value of $$ {4^{10+n}}.{16^{3n-4}}\over4^{7n}$$ is:

$$ \sqrt{217+\sqrt{48+\sqrt{256}}}=?$$

If $$  3 ^{2x-y}=3^{x+y}=\sqrt{27}$$ then the value of y is

If $$ {2^{2n-1}}={1\over8^{n-3}}$$,then the value of n is:

If 3 ^(X-Y)=27 and 3 ^(X+Y)=243, then X is equal to:

If 5^a=3125, then the value of 5^(a-3) is: