document.write( "Question 674253: A fair coin is tossed until a head appears.The probability that 3 throws are necessary.\r
\n" ); document.write( "\n" ); document.write( "I considered 1/2*1/2*1/2=1/8\r
\n" ); document.write( "\n" ); document.write( "But the answer is 1/2*1/2 DISABLED_event_only= 1/4.\r
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Algebra.Com's Answer #419117 by ewatrrr(24785) $\"\"$ $\"About$

You can put this solution on YOUR website!

 
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document.write( "Hi
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document.write( "consider the sample space: 
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document.write( "P(3 throws necessary) = 1-6/8 = 2/8 = 1/4
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document.write( "THT
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document.write( "THH 
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document.write( "HHH
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document.write( "HHT
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document.write( "HTH
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document.write( "HTT\r
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document.write( "TTT
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document.write( "TTH\r
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