document.write( "Question 700038: There are three urns:first urn contains 1 white,2red,3green balls,second urn contains 2 white,1red,1green balls and third urn contains 4 white,5red,3green balls.
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document.write( "Two balls are drawn from an urn chosen at random.These are found to be one white and one green.Probability that balls are drawn from third urn is:
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document.write( "(A)15/59, (B)14/59, (C)13/59, (D)12/59\r
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document.write( "Please explain the procedure also!In book only the correct answer is given 15/59....but i dont get how to slove it,so plz explain the procedure,plz. \n" );
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Algebra.Com's Answer #431811 by KMST(5328)![]() ![]() You can put this solution on YOUR website! DISCLAIMER: \n" ); document.write( "I do not memorize procedures, and I do not follow procedures unless someone makes me. \n" ); document.write( "What follows is my just my understanding of the problem. \n" ); document.write( "Your teacher may have a procedure to reach the solution more efficiently. \n" ); document.write( " \n" ); document.write( "If an urn chosen at random, the third urn will be chosen \n" ); document.write( "(In fact, each of the three urns will be chosen \n" ); document.write( " \n" ); document.write( "If the first urn is chosen (with 6 balls, including 1 white and 3 green), \n" ); document.write( "the probability of drawing the white ball first is \n" ); document.write( "After that, the probability of drawing one of the 3 green balls from the 5 balls left in the urn is \n" ); document.write( "So, the probability of drawing a white ball followed by a green ball from the first urn is \n" ); document.write( "Similarly, the probability of drawing a green ball followed by a white ball from the first urn is \n" ); document.write( "The probability of drawing a white ball and a green ball (in any order) from the first urn is \n" ); document.write( " \n" ); document.write( "If the second urn is chosen (with 4 balls, including 2 white and 1 green), \n" ); document.write( "the probability of drawing a white ball and a green ball (in any order) is \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "If the third urn is chosen (with 12 balls, including 4 white and 3 green), \n" ); document.write( "the probability of drawing a white ball and a green ball (in any order) is \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "If the drawing of two balls was done \n" ); document.write( "you would expect the first urn to be chosen 165 times, \n" ); document.write( "drawing one a white ball and a green ball (in any order) from the first urn \n" ); document.write( " \n" ); document.write( "The second urn would be also chosen 165 times, \n" ); document.write( "drawing one a white ball and a green ball (in any order) from the second urn \n" ); document.write( " \n" ); document.write( "The third urn would be also chosen 165 times, \n" ); document.write( "drawing one a white ball and a green ball (in any order) from the third urn \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "In all, a white ball and a green ball (in any order) would be drawn (from an urn chosen at random) \n" ); document.write( " \n" ); document.write( "Of those 118 times, 30 times it would be from the third urn, \n" ); document.write( "so if a white ball and a green ball (in any order) had been drawn \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " |