Answer:
Step-by-step explanation:
englargment
Answer:
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Explanation:
Simulate (build a table) the growing of the number of pennies for some nights to figure out the pattern:
First night: 1 penny = 2⁰
Second night: 1 × 2 pennies = 2¹
Third night: 2 × 2 = 2²
Fourth nigth: 2² × 2 = 2³
nth night: 2ⁿ⁻¹
You want 2ⁿ⁻¹ ≥ 2,000,000,000
Which you solve in this way:
- n-1 log (2) ≥ log (2,000,000,000)
- n - 1 ≥ log (2,000,000,000) / log (2)
Since n is number of days, it is an integer number, so n ≥ 32.
Hence, she will have a total of more than $ 2 billion after 32 days.
You can prove that by calculating 2³² = 2,147,483,648.
