High School

A culture of bacteria has an initial population of 400 bacteria and doubles every 2 hours. Using the formula:

[tex] P_t = P_0 \cdot 2^{\frac{t}{d}} [/tex]

where:
- [tex] P_t [/tex] is the population after [tex] t [/tex] hours,
- [tex] P_0 [/tex] is the initial population,
- [tex] t [/tex] is the time in hours,
- [tex] d [/tex] is the doubling time,

what is the population of bacteria in the culture after 13 hours, to the nearest whole number?

Answer :

To find the population of bacteria in the culture after 13 hours, we can use the formula:

[tex]\[ P_t = P_0 \cdot 2^{\frac{t}{d}} \][/tex]

where:
- [tex]\( P_t \)[/tex] is the population after [tex]\( t \)[/tex] hours,
- [tex]\( P_0 \)[/tex] is the initial population,
- [tex]\( t \)[/tex] is the time in hours,
- [tex]\( d \)[/tex] is the doubling time, which is 2 hours in this case.

Here is a step-by-step breakdown of the solution:

1. Identify the given values:
- Initial population ([tex]\( P_0 \)[/tex]) = 400 bacteria
- Doubling time ([tex]\( d \)[/tex]) = 2 hours
- Time elapsed ([tex]\( t \)[/tex]) = 13 hours

2. Substitute the values into the formula:

[tex]\[ P_t = 400 \cdot 2^{\frac{13}{2}} \][/tex]

3. Calculate the exponent:

- First, calculate [tex]\( \frac{13}{2} \)[/tex], which equals 6.5.

4. Calculate [tex]\( 2^{6.5} \)[/tex]:

- This involves finding the value of 2 raised to the power of 6.5.

5. Multiply by the initial population (400):

- Once you have [tex]\( 2^{6.5} \)[/tex], multiply it by 400 to find [tex]\( P_t \)[/tex].

6. Round the result to the nearest whole number:

- After performing these calculations, the population of bacteria in the culture after 13 hours is approximately 36,204 bacteria.

So, the population of bacteria after 13 hours is 36,204.

Other Questions