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    • Question

      There are ‘x’ white balls and 5 black balls in a

      jar. If the probability of picking a white ball is 2/3, then calculate the probability that the two chosen balls are not of the same colour.
      A 10/21 Correct Answer Incorrect Answer
      B 32/44 Correct Answer Incorrect Answer
      C 21/40 Correct Answer Incorrect Answer
      D 11/12 Correct Answer Incorrect Answer
      E None of these Correct Answer Incorrect Answer

      Solution

      ATQ, Total balls = x + 5 So, x/(x + 5) = 2/3 Or, 3x = 2x + 10 So, x = 10 Desired Probability = (10C1 × 5C1)/(15C2) = (2 × 10 × 5)/(15 × 14) = 10/21

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