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A bag contains 15 balls, out of which some are white and the otherblack. If the probability of drawing a black ball at random from the- then find how many white balls are there in the bag. |
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Answer» No Of Balls = 15No Of Blue Balls = xNo Of Red Balls = 15 - xProbability of taking a red ball is; P(E) = 15 - x15 After 5 red balls are added,No of balls = 15 + 5 = 20No of blue balls = xNo of Red Balls = (15 - x) + 5 = 20 - xProbability of taking a red ball is; P(E) = 20 - x20 According to your question, 15 - x x 2 = 20 - x15 20 30 - 2x = 20 - x15 20 600 - 40 x = 300 - 15 x 300 =25 xx = 12 |
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