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) Responses 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 60 bacteria. Start Fraction n over 2 End Fraction equals 120 ; at 8:00 a.m., there were 60 bacteria. 2n=120; at 8:00 a.m., there were 240 bacteria. 2 n equals 120 ; at 8:00 a.m., there were 240 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.
The correct equation that represents the number of bacteria, n, at 8:00 a.m. is 2n = 120. Therefore, at 8:00 a.m., there were 60 bacteria.
The equation that represents the number of bacteria, n, at 8:00 a.m is 2n = 120.
To solve for n, divide both sides of the equation by 2:
n = 120/2
n = 60
Therefore, at 8:00 a.m there were 60 bacteria.
So the correct answer is:
2n = 120; at 8:00 a.m., there were 60 bacteria.
To solve this problem, we need to determine the growth rate of the bacteria and then work backwards to find the number of bacteria at 8:00 a.m.
We are given that the bacteria doubles every hour. This means that the growth rate is a factor of 2.
Since there is 1 hour between 8:00 a.m. and 9:00 a.m., we need to divide the number of bacteria at 9:00 a.m. by 2 to find the number of bacteria at 8:00 a.m.
Therefore, the correct equation representing the number of bacteria, n, at 8:00 a.m. is:
n/2 = 120
Simplifying this equation, we can multiply both sides by 2:
2n/2 = 120 * 2
This cancels out the 2 on the left side of the equation:
n = 240
Therefore, at 8:00 a.m., there were 240 bacteria.