Now that you are jugging formulas like a pro, let me ask you this: How could you combine the growth rate $k=\frac{n}{t}$ and the growth formula $N=2^{****}{N}_f$ from before?

a$)k=lo{g}_{10}\frac{N_0**N}{t}$

b$)k=lo{g}_2\frac{\frac{N_1}{N_2}}{t}$

c$)$

d$)k$