A fair coin is tossed three times. Find the probability of getting two heads and one tail.

  • A \(\frac{1}{2}\)
  • B \(\frac{3}{8}\)
  • C \(\frac{1}{4}\)
  • D \(\frac{1}{8}\)
waec 2006mathematics

The correct answer is B. \(\frac{3}{8}\)

Pr(head) = \(\frac{1}{2}\), Pr(tail) = \(\frac{1}{2}\):Pr(2 heads)

= \(\frac{1}{2}\) x \(\frac{1}{2}\) = \(\frac{1}{4}\)

Pr(2 heads and tail) 3 times

= (\(\frac{1}{4}\) x \(\frac{1}{2}\)) x 3

= \(\frac{3}{8}\)

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