Set 3: Exponential Functions (Advanced)

**Choice A is the best answer.** After 1 half-lives: 640 / 2 to the power of 1 = 320 grams

Explanation

Answer: A

PROBLEM

A substance with half-life of 1 hour starts at 640 grams. How many grams remain after 1 hours?

320

✓ Correct

319

318

160

Detailed Explanation

Choice A is the best answer. After 1 half-lives: 640 / 2 to the power of 1 = 320 grams

Why others are wrong:

B: 319 is incorrect because it does not satisfy the equation.

C: 318 is incorrect because it does not satisfy the equation.

D: 160 is incorrect because it does not satisfy the equation.