Question

A lab is growing bacteria in a culture dish. The amount of bacteria in the dish doubles every 3 hours. Initially, there are 500 bacteria in the dish. How many are in the dish after 9 hours A. 4,500 B. 4,000 C. 1,500 D. 13,500

Answer 1

D- 500*3
 *3
 *3 =  13500

Answer 2

Answer: B. 4,000

Step-by-step explanation:

Given: The initial amount of bacteria in the dish A= 500

Since, The amount of bacteria in the dish doubles every 3 hours.

The multiplicative rate of change after every 3 hours = 2

Time period = 3 hours

By exponential function, we have the amount of bacteria after time period 'x' is given by :-

$y=Ab^x$,  where A is the initial amount , b is the multiplicative rate of change in time period x.

Number of 3 hours period in 9 hours = 3

Therefore, x=3

Therefore, the amount of bacteria in the dish after 9 hours is given by :_

$y=500(2)^3=500\times8=4000$