Computer Science I / Sequences and Series
Practice question · Numerical answer

A geometric series starts at n = 0 with ratio r = 0.2. What does it sum to?

Hints
  1. Use 1 divided by (1 - r).
  2. 1 - 0.2 = 0.8.
Show the answer

1.25 (answers within ±0.001 count)

Why

1 divided by 0.8 is 1.25. Note how much smaller this is than the r = 0.5 case, which sums to 2: the closer the ratio sits to 1, the more slowly the series converges and the more terms a computer must add for a given accuracy.

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