Answer
4
Work Step by Step
$\log (\log 10^{10000})$
Since no base is provided, we assume it's 10
Apply the Third Law of Logarithms to the log inside the parenthesis
$\log (10000\log 10)$
$\log(10000\times1)$ (since $\log_x x$ = 1)
$\log 10000$
$\log 10^4$
Apply the Third Law of Logarithms again
4$\times$$\log 10$
4$\times$1
=4
