When a certain coin is flipped, the probability of heads is 0.5.
If the coin is flipped 6 times, what is the probability that
there are exactly 3 heads? Out of 6 tosses, exactly 3 heads
implies exactly 3 tails. You can get 3 heads and 3 tails in
various ways: HHHTTT, HHTHTT, TTTHHH etc How many such ways are
there? We just need to find the number of ways of arranging 3 Hs
and 3 Ts in a row. This can be done in 6!/3!*3! = 20 ways (the 3
Hs are identical and the 3 Ts are identical) Probability of
obtaining HHHTTT = (0.5)*(0.5)*(0.5)*(0.5)*(0.5)*(0.5)
Probability of obtaining 3Hs and 3 Ts in any order = (0.5)^6 *
20 = 5/16 Check out this post for a discussion on binomial
probability concept:http://www.veritasprep.com/blog/2012/02 ...
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