Why is this change of log base as such?

Question

I found the following in a textbook:

I can't understand how this happend. Isn't the denominator suppose to be $log_{e}2$ ?

Answer 1

This is a typo in the book. The general rule for the conversion of logarithms with different bases $a$ and $b$ is $$ \log_a(x) = \dfrac{\log_b(x)}{\log_b(a)} \;. $$