document.write( "Question 203046: If two numbers are randomly chosen without replacement from {1, 2, 3, 4, 5}, what is the probability their sum is greater than their product? Express your answer as a common fraction. \n" ); document.write( "
Algebra.Com's Answer #484463 by albertemc(1)\"\" \"About 
You can put this solution on YOUR website!
Sorry jsmall I'ma afraid your answer is wrong.\r
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\n" ); document.write( "\n" ); document.write( "The question is asking : if 2 numbers are picked randomly WITHOUT REPLACEMENT. \r
\n" ); document.write( "\n" ); document.write( "hence, while you may use the multiplicative probability properties, the second probability of drawing a number that is not 1 is not 5/6 (further more , the student is asking about the numbers (1,2,3,4,5) , 6 is not included\r
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\n" ); document.write( "\n" ); document.write( "But lets assume we are dealing with (1,2,3,4,5,6) when you pick your first choice, you have 5/6 chance of picking numbers not 1, \r
\n" ); document.write( "\n" ); document.write( "namely, 2,3,4,5,6.\r
\n" ); document.write( "\n" ); document.write( "in your second choice, since you are drawing without replacement, you have only 5 options left, assumed you have picked 4 for your first choice, you now have 1,2,3,5,6 to choose from, however, you don't want to choose one, so you have 4/5 chance of picking numbers not 1.\r
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\n" ); document.write( "\n" ); document.write( "hence, the probability of not drawing 2 numbers whose sum is greater than product is (5/6)*(4/5) = (4/6) = 2/3.\r
\n" ); document.write( "\n" ); document.write( "probability of drawing 2 numbers whose sum is greater than product is then 1/3\r
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\n" ); document.write( "\n" ); document.write( "Alternatively, you may see that there are (6 choose 2) = 15 ways to pick 2 random numbers out of 6. And there are 5 ways to choose 2 numbers such that 1 is included (1,2) (1,3) ..... (1,5). since the probability of drawing any two numbers are the same, therefore, 5/15 = 1/3 is the probability of drawing 2 numbers whose sum is greater than their product.\r
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\n" ); document.write( "\n" ); document.write( "So I think you have all the tools you need to solve the problem with just (1,2,3,4,5) :)
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