Out of 70 schools, 42 of them can be attended by boys and 35 can be attended by girls. If a pupil is selected at random from these schools, find the probability that he/ she is from a mixed school.

  • A \(\frac{1}{11}\)
  • B \(\frac{1}{10}\)
  • C \(\frac{1}{6}\)
  • D \(\frac{1}{5}\)
waec 2018furthermathematics

The correct answer is B. \(\frac{1}{10}\)

Let the number of mixed schools be S

The number of boys only = 42 - S

The number of girls only = 35 - S

(42 - S) + S + (35 - S) = 77 - S = 70

\(\implies\) S = 7

\(Probability = \frac{7}{70} = \frac{1}{10}\)

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