Question

The relative growth rate for a certain type of bacteria population is 85% per hour. A small culture has formed and in just 2 hours the count shows to be 12,500 bacteria in the culture. What is the initial number of bacteria in the culture?

Answer 1

the initial number of bacteria in the culture is 3,655.

Answer 2

Let us assume the initial number of bacteria in the culture = x
After 1 hour,
The number of bacteria = 185x/100
= 1.85x
After 2 hours,
The number of bacteria = (185 * 1.85x)/100
= 3.42x
So
3.42x = 12500
x = 12500/3.42
= 3654.97
= 3655
From the above deduction, we can conclude that the initial number of bacteria in the culture is 3655.