Question

A population of bacteria is growing at a rate of 20% per hour. If the population starts at 320, what is it an hour later?

Answer 1

384.

Explanation:

The population is given by the expression;

`Y(t) = Pr^(t)`

Where;

Y(t) is the number of bacteria at time, t.

P is the starting amount.

r is the growth rate.

Given that, P = 320, r = 20% = 0.2, t = 1

Substituting the parameters into the equation;

`Y(t) = Pr^(t)`

Y(1) = 320 * 0.2¹

Y(1) = 320 * 0.2

Y(1) = 64.

Therefore, the population of bacteria increases hourly by 64.

An hour later; 320 + 64 = 384.