You find a coin that doubles in value every time you leave it alone for an hour. If it starts at one cent, how long will it take to reach $1?
Category: Brain Teasers · Difficulty: expert
Hint: Think about how many doublings are needed.
Answer
6 hours
Explanation
The coin doubles in value: 0.01, 0.02, 0.04, 0.08, 0.16, 0.32, 0.64, 1.00 – reaching $1 takes 6 doublings.
This is a expert brain teasers riddle — one of the harder riddles here. The answer is 6 hours.
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