document.write( "Question 981078: If a drawer has 4 red socks and 4 blue socks\r
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document.write( "a) if 2 are drawn what is the probability of a match?
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document.write( "b) if 3 are drawn what is the probability of a match?
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document.write( "c) What is the probability of having all one color after 4 draws?\r
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document.write( "I have this so far..
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document.write( "a) 3/7
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document.write( "P (Red) on first draw = 4/8
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document.write( "P (Red) on second draw = 3/7
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document.write( "4/8 * 3/7 = 12/56
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document.write( "P (Blue) is the same so
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document.write( "12/56 + 12/56= 3/7\r
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document.write( "b)100% chance\r
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document.write( "c) no clue what steps to take.\r
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document.write( "Any help is appreciated!\r
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Algebra.Com's Answer #602100 by jim_thompson5910(35256)![]() ![]() ![]() You can put this solution on YOUR website! Throughout the problem, I'm assuming no replacements are made. \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "a)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Case 1: You pull out a red sock on the first draw\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "P(drawing another red) = (# of red)/(# total) \n" ); document.write( "P(drawing another red) = 3/7\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "---------------------------------\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Case 2: You pull out a blue sock on the first draw\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "P(drawing another blue) = (# of blue)/(# total) \n" ); document.write( "P(drawing another blue) = 3/7\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "---------------------------------\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So either way, it's 3/7. You are correct.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "=======================================================\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "b)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "You are correct. There are only two colors. By the time you get to the third draw, you'll either pick red or blue. Either you have a match in the first two draws or you will have a match with the third draw (with one of the first two draws).\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So that's why it's 100% or 1.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "=======================================================\r \n" ); document.write( "\n" ); document.write( "c)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Case 1: You draw red on the first draw\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "P(2nd red) = 3/7 \n" ); document.write( "P(3rd red) = 2/6 \n" ); document.write( "P(4th red) = 1/5\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "P(4 reds) = (3/7)*(2/6)*(1/5) \n" ); document.write( "P(4 reds) = (3*2*1)/(7*6*5) \n" ); document.write( "P(4 reds) = 6/210 \n" ); document.write( "P(4 reds) = 1/35\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "---------------------------------\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Case 2: You draw blue on the first draw\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "P(2nd blue) = 3/7 \n" ); document.write( "P(3rd blue) = 2/6 \n" ); document.write( "P(4th blue) = 1/5\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "P(4 blues) = (3/7)*(2/6)*(1/5) \n" ); document.write( "P(4 blues) = (3*2*1)/(7*6*5) \n" ); document.write( "P(4 blues) = 6/210 \n" ); document.write( "P(4 blues) = 1/35\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Either way, the answer is 1/35 \n" ); document.write( " \n" ); document.write( " |