Waiting More Than Five Flips

Probability
Geometric Distribution
Easy
A fair coin is flipped until the first head appears. What is the probability that more than five flips are required?
Hint 1

More than five flips are required exactly when the first five flips are all tails.

Hint 2

Multiply the probability of five consecutive tails.

Show worked solution
  1. 1. Translate the event

    Needing more than five flips means the first five flips are all tails.

  2. 2. Compute the probability

    Each flip is tails with probability , independently.

Answer: 1/32

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