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Probability, SM-Bank 087

A bag contains a number of identical red, blue and green discs.

The probability of drawing a red disc is \(\dfrac{2}{3}\) and the probability of drawing a blue disc is \(\dfrac{1}{4}\).

What is the probability of drawing a green disc?  (2 marks)

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\(\dfrac{1}{12}\)

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\(\text{The sum of all probabilities in an event = 1}\)

\(P\text{(Green)}\) \(=1-\Bigg(\dfrac{2}{3}+\dfrac{1}{4}\Bigg)\)
  \(=1-\Bigg(\dfrac{8}{12}+\dfrac{3}{12}\Bigg)\)
  \(=1-\dfrac{11}{12}=\dfrac{1}{12}\)