Question

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bacteria grow at different rates depending on the temperature. at 39°f (6°c), listeria monocytogenes can double its population every 36 hours. but at 55°f (13°c), it doubles every six hours.

let’s say you have two containers of sliced turkey. the first container is held at 39°f (6°c). the second container is held at 55°f (13°c). each container starts with a single listeria bacterium. how many bacteria will be in each container after three days (72 hours)? complete the tables to show the growth of the bacteria in each container.

first container, at 39°f (6°c)

time	bacteria
36 hours
72 hours

second container, at 55°f (13°c)

time	bacteria
6 hours
12 hours
18 hours
24 hours
30 hours
36 hours
42 hours
48 hours
54 hours
60 hours
66 hours
72 hours

Explanation:

First Container (39°F, 6°C)

Step1: Initial Bacteria (0 hours)

Starts with 1 bacterium.
$1$

Step2: After 36 hours

Doubles every 36 hours, so $1 \times 2 = 2$.
$2$

Step3: After 72 hours

Doubles again (from 36 to 72 hours is another 36 hours), so $2 \times 2 = 4$.
$4$

Second Container (55°F, 13°C)

Step1: Initial Bacteria (0 hours)

Starts with 1 bacterium.
$1$

Step2: After 6 hours

Doubles every 6 hours, so $1 \times 2 = 2$.
$2$

Step3: After 12 hours

Doubles again, $2 \times 2 = 4$.
$4$

Step4: After 18 hours

Doubles again, $4 \times 2 = 8$.
$8$

Step5: After 24 hours

Doubles again, $8 \times 2 = 16$.
$16$

Step6: After 30 hours

Doubles again, $16 \times 2 = 32$.
$32$

Step7: After 36 hours

Doubles again, $32 \times 2 = 64$.
$64$

Step8: After 42 hours

Doubles again, $64 \times 2 = 128$.
$128$

Step9: After 48 hours

Doubles again, $128 \times 2 = 256$.
$256$

Step10: After 54 hours

Doubles again, $256 \times 2 = 512$.
$512$

Step11: After 60 hours

Doubles again, $512 \times 2 = 1024$.
$1024$

Step12: After 66 hours

Doubles again, $1024 \times 2 = 2048$.
$2048$

Step13: After 72 hours

Doubles again, $2048 \times 2 = 4096$.
$4096$

Filling the Tables:

First Container, at 39°F (6°C)

Time	Bacteria
36 hours	2
72 hours	4

Second Container, at 55°F (13°C)

Time	Bacteria
6 hours	2
12 hours	4
18 hours	8
24 hours	16
30 hours	32
36 hours	64
42 hours	128
48 hours	256
54 hours	512
60 hours	1024
66 hours	2048
72 hours	4096

Answer:

• First Container (72 hours): 4 bacteria
• Second Container (72 hours): 4096 bacteria

(And the tables are filled as shown above.)