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Question

A box contains 8 yellow marbles, ‘x’ blue marbles and 12 white marbles. A box contains 5 yellow marbles, 2 blue marbles and 3 white marbles. The probability of drawing a blue marble at random from the box is 1/6. If (x/2) blue marbles from the box is transferred to the bag, then find the probability of drawing a blue marble and a white marble from the box

A 2/11 Correct Answer Incorrect Answer
B 1/11 Correct Answer Incorrect Answer
C 2/13 Correct Answer Incorrect Answer
D 2/15 Correct Answer Incorrect Answer
E None of these Correct Answer Incorrect Answer

Solution

According to the question, x/(8 + x + 12) = 1/6 => 5x = 20 => x = 4 Therefore, number of blue marbles transferred to box = x/2 = 2 Total number of blue marbles in the bag after the transfer = 2 + 2 = 4 Total number of marbles in the box after the transfer = 5 + 2 + 3 + 2 = 12 Required probability = (4C1 × 3C1 )/12C2 = 2/11

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