Question
A bag contains 6 yellow balls, 8 purple balls, and 4 black
balls. Two balls are drawn at random. Find the probability that the two balls are purple.Solution
Number of ways of selecting two purple balls = 8 Câ‚‚
Total number of balls = 6 + 8 + 4 = 18
Number of ways of selecting two balls = 18 Câ‚‚
Probability = 8 C₂ ÷ 18 C₂ = (8 × 7) ÷ (18 × 17) = 56 ÷ 306 = 28/153
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