Logarithms: ACT Math Practice Question

Try the following ACT math practice question that tests your understanding of logarithmic operations.

If $3 = k\cdot 2^r$ and $15 = k\cdot 4^r$, then $r =$

1. $\quad -\log_{2}5$
2. $\quad \log_{5}2$
3. $\quad \log_{10}5$
4. $\quad \log_{2}5$
5. $\quad \dfrac{5}{2}$

Choice D

Video Explanation