Answer
True.
Work Step by Step
First, divide both sides of the equation by $50$ to get $$0.345^t=\frac{4}{50}$$ Next, take the $\log$ of both sides to get $$\log 0.345^t=\log(4/50)$$ Since $\log a^b=b \log a$ for all positive values of $a$, $$t \log 0.345 = log(4/50)$$ Finally, divide both sides by $\log 0.345$ to get $$t = \frac{\log(4/50)}{\log 0.345}$$ Thus, the statement is true.