Answer
a) $N(t)=1500\cdot 2^t$
b) $N(24)\approx2.52\cdot 10^{10}$ bacteria
Work Step by Step
a) The base form of exponential functions if $f(x)=n\cdot b^x$, where $n$ is the initial number and $b$ is the growth factor. In this exercise, there are initially $1500$ bacteria, so that corresponds to $n$. And the growth factor is $2$, so that corresponds to $b$. Thus, the equation:
$N(t)=1500\cdot 2^t$
b) $N(24)=1500\cdot 2^{24}\approx2.52\cdot 10^{10}$ bacteria
