The number of strands of bacteria present at 12 hours will be 120. Then the correct option is D.
What is an exponent?
Let a is the initial value and x is the power of the exponent function and b is the increasing factor.
The exponent is given as
y = a(b)ˣ
A population culture begins with 15 strands of bacteria and then doubles every 4 hours.
This can be modeled as
[tex]\rm y =15 \times (2)^{t/4}[/tex], where t is time in hours and y is the number of bacteria.
The number of strands of bacteria present at 12 hours will be
[tex]\rm y =15 \times (2)^{12/4}[/tex]
Simplify the equation, then the number of bacteria will be
y = 15 × 2³
y = 15 × 8
y = 120
The number of strands of bacteria present at 12 hours will be 120.
Then the correct option is D.
More about the exponent link is given below.
https://brainly.com/question/5497425
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