7
Answer: CSet 1: Exponential Functions (Advanced)
Explanation
PROBLEM
A substance with half-life of 1 hour starts at 320 grams. How many grams remain after 2 hours?
A substance with half-life of 1 hour starts at 320 grams. How many grams remain after 2 hours?
A.
79
B.
81
C.✓ Correct
80
D.
78
Detailed Explanation
Choice C is the best answer. After 2 half-lives: 320 / 2 to the power of 2 = 80 grams
Why others are wrong:
A: 79 is incorrect because it does not satisfy the equation.
B: 81 is incorrect because it does not satisfy the equation.
D: 78 is incorrect because it does not satisfy the equation.