The question asks to find the value equivalent to the power tower expression $2^{2^{2^2}}$. We evaluate this expression starting from the top exponent downwards.
The calculated value is $2^{16}$. Comparing this with the given options:
The expression $2^{2^{2^2}}$ is equivalent to $2^{16}$, which corresponds to Option 3.
Identify the number that will replace the question mark in the second equation based on the relationship represented in the first equation.

Simplify: $\frac{\sqrt{16x^4 - 72x^2y^2 + 81y^4}}{\sqrt{4x^2 - 12xy + 9y^2}} - (2x - 3y)$, given that $2x > 3y$.
What value should come in the place of question mark (?) in the following equation?
$(0.008\div?) + (0.006 \div 0.03) + (0.008 \div 0.04) =0.5$