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

Question

𝑛
, at 8:00 a.m? How many bacteria were there?(1 point)
Responses

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

n2=120
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.

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

n2=120
𝑛
2
=
120
; at 8:00 a.m., there were 60 bacteria.

Answer 1

To determine the number of bacteria at 8:00 a.m., given that the bacteria double every hour and there were 120 bacteria at 9:00 a.m., we can set up the following equation.

If \( n \) is the number of bacteria at 8:00 a.m., then after one hour (from 8:00 a.m. to 9:00 a.m.) the number of bacteria would be \( 2n \). Therefore, we have:

\[ 2n = 120 \]

Now, we can solve for \( n \):

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

So, the equation that represents the number of bacteria at 8:00 a.m. is \( 2n = 120 \), and at 8:00 a.m., there were 60 bacteria.

Thus, the correct response is:

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