A culture of a certain bacteria doubles every hour. At 9:00 a.m, there were already 120 bacteria. Which equation represents the number of bacteria, n, at 8:00 a.m? How many bacteria were there?(1 point)

Question

Responses

2n=120; at 8:00 a.m., there were 240 bacteria.
2 n equals 120 ; at 8:00 a.m., there were 240 bacteria.

2n=120; at 8:00 a.m., there were 60 bacteria.
2 n equals 120 ; at 8:00 a.m., there were 60 bacteria.

n/2=120; at 8:00 a.m., there were 240 bacteria.
Start Fraction n over 2 End Fraction equals 120 ; at 8:00 a.m., there were 240 bacteria.

n/2=120; at 8:00 a.m., there were 60 bacteria.

Answer 1

To find the number of bacteria at 8:00 a.m., we need to consider that the bacteria double every hour. Since there were 120 bacteria at 9:00 a.m., we can determine the number of bacteria at 8:00 a.m. by halving the number at 9:00 a.m.

If we let \( n \) represent the number of bacteria at 8:00 a.m., the relationship can be expressed as:

\[ 2n = 120 \] where \( n \) is the number of bacteria at 8:00 a.m.

Therefore, if we solve for \( n \):

\[ n = \frac{120}{2} = 60 \]

So, at 8:00 a.m., there were 60 bacteria.

Now, matching it to the provided responses, we find:

• 2n=120; at 8:00 a.m., there were 60 bacteria.

This is the correct representation and answer.