Question

A certain bacteria doubles every day. If there were 400 in original culture, how many would be present after 3 days?

Answer 1

`3200\text{ bacteria}`

Step-by-step explanation

Initially, there are 400 bacteria in the culture and the culture doubles every day.

This describes an exponential function with an initial value of 400 and a factor of 2 (since it doubles):

`y=a\cdot b^x`

where a = initial number = 400

b = factor = 2

x = number of days

Therefore, after 3 days, we have that the amount of bacteria that would be present is:

`\begin{gathered} y=400\cdot2^3 \\ y=3200 \end{gathered}`