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    Question

    A bag contains 35 white and some black balls. If the

    probability of drawing a black ball from the bag is 1.8 times that of drawing a white ball, find the number of black balls in the bag.
    A 65 Correct Answer Incorrect Answer
    B 63 Correct Answer Incorrect Answer
    C 62 Correct Answer Incorrect Answer
    D 67 Correct Answer Incorrect Answer

    Solution

    Number of white balls = 35 Let x be the number of black balls. Total number of balls in the bag = 35 + x Also, the probability of drawing a black ball from the bag is 1.8 times that of drawing a white ball. ⇒ x/(35 + x) = 1.8[35/(35 + x)] ⇒ x = 1.8 × 35 = 63 Hence, the number of black balls in the bag = 63

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