5

Set 2: Exponential Functions (Advanced)

Explanation

Answer: A

A colony of ants grows from 2,000 to 32,000 in 5 weeks. Assuming exponential growth, what is the weekly growth factor?

A.

2

✓ Correct
B.

16

C.

4

D.

6

Detailed Explanation

Choice A is correct. Choice A is the correct answer. Find the weekly growth factor. 1. Formula: N(t)=N0(b)tN(t) = N_0(b)^t where N0=2000N_0 = 2000, N(5)=32000N(5) = 32000. 2. Solve: 32000=2000(b)532000= 2000(b)^5, so b5=16b^5 = 16. 3. Recognize: 16=2416= 2^4, but we need b5=16=24b^5 = 16 = 2^4, so b=2b = 2. 4. Verify: 2000(2)5=2000(32)=640002000(2)^5 = 2000(32) = 64000... Strategic Tip: The factor multiplied over all periods is 16, so weekly factor is 165=2\sqrt[5]{16} = 2. Choice B is incorrect because this is the total growth factor, not weekly. Choice C is incorrect because this would give 2000(4)5=2,048,0002000(4)^5 = 2,048,000. Choice D is incorrect because the calculation doesn't match.

Key Steps:

The correct answer is 2

Why others are wrong:
B: Choice B is incorrect and may result from a calculation error.
C: Choice C is incorrect and may result from a calculation error.
D: Choice D is incorrect and may result from a calculation error.

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