To find the number of bacteria at 8:00 a.m., we need to account for the doubling behavior of the bacteria. Since the bacteria double every hour, we can set up the following relationship:
- At 9:00 a.m., the number of bacteria is 120.
- At 8:00 a.m., before they doubled, the number of bacteria would be half of what it was at 9:00 a.m.
This means we can express the number of bacteria at 8:00 a.m. as:
\[ n = \frac{120}{2} \]
or
\[ n = 60 \]
To find the equation, we can rearrange the numbers based on the doubling nature:
If \( n \) represents the number of bacteria at 8:00 a.m., we know that:
\[ 2n = 120 \]
This means that the equation \( 2n = 120 \) represents the situation correctly, where you double the number of bacteria from 8:00 a.m. to 9:00 a.m.
Thus, the correct response is:
2n = 120; at 8:00 a.m., there were 60 bacteria.
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