3

Set 15: Exponential Functions

Explanation

Answer: A

Two investments:

  • Investment P: $1,000 growing at 10% annually
  • Investment Q: $800 growing at 15% annually

After many years, which will be worth more?

A.

Investment Q

✓ Correct
B.

Investment P

C.

They will be equal

D.

Cannot determine

Detailed Explanation

Choice A is correct. Choice A is the correct answer. Compare growth factors over the long term. 1. Investment P: P(t)=1000(1.10)tP(t) = 1000(1.10)^t. 2. Investment Q: Q(t)=800(1.15)tQ(t) = 800(1.15)^t. 3. Long-term: 1.15>1.101.15> 1.10, so Q's base is larger. 4. Conclusion: As tt \to \infty, the larger base dominates, so Q eventually exceeds P. Strategic Tip: In exponential growth, larger base always wins in the long run. Choice B is incorrect because despite higher initial value, lower growth rate loses. Choice C is incorrect because different bases mean they diverge. Choice D is incorrect because we can determine this from the growth rates.

Key Steps:

The correct answer is Investment Q

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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