Multiple choice

A fair coin is tossed repeatedly. The probability of getting a different result in the fifth toss, than those obtained in the first four tosses is 1/4x. Find x.

  1. 1

  2. 2

  3. 3

  4. 4

  5. None

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Either 4 heads and one tail in the fourth or 4 tails and 4 heads. Probability = 2(0.5)^5 = 1/16 = 1/4x which gives x = 4.