๐Ÿ“ˆ Economic Growth (1 video)

  1. The Rule of 72 and Compound Growth. Why the rule of 72 works, three bonus exercises, and transcript: web, PDF.

THUMBNAIL PROBLEM: At 2% daily interest, how long for $1 to grow to $1B?

SOLUTION:

  • Doubling time โ‰ˆ 72 รท 2 = 36 days.
  • 1B = 1000ยณ. So, โ†‘1B โ‰ˆ Doubling 30 times.
  • Answer โ‰ˆ 36 ร— 30 = 1080 days โ€” or roughly 3 years.

(The actual answer is 1046.5โ€ฆ days โ€” or 2.867โ€ฆ years. )

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