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coin

by ketkoag » Tue Jun 09, 2009 7:12 am
A coin is tossed 3 times. What is the probability that it will be up with the same side in all the 3 times?

[spoiler]please explain how answer is ¼..[/spoiler]

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by sacx » Tue Jun 09, 2009 7:22 am
total possibilities = 8

HHH
HHT
HTH
THH
TTT
TTH
THT
HTT

same side up = 2 (HHH,TTT)

probability = 2/8 = 1/4
SACX

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by yogami » Tue Jun 09, 2009 10:33 am
in order to get same side up all three times you need to get HHH or TTT
Hence the probability is (1/2)^3 + (1/2) ^3 = 1/4
200 or 800. It don't matter no more.