A culture starts with 500 bacteria, and the number doubles every hour. How many bacteria are there after 4 hours?
Answer and explanation
Correct answer: B. 8,000
- Step 1: Doubling four times gives a factor of 2^4 = 16. Step 2. 500 x 16 = 8,000. Answer: 8,000. Why not the others: Exponential growth multiplies by 2 each hour; adding or using the wrong power fails.
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