Do a binomial expansion of (T + H)400.
Evaluate the 221st term for H= 1/2 and T = 1/2 and you have the answer.
There is some short cut to get that term quickly, but I've forgotten it.
There is a 1/8 chance to land three heads.
1/2 apex It does not matter what each prior flip's result was. Each flip has a probability of 0.5 heads or tails. Coins do not have "memory".
one fourth
It is 0.1042
It is 0.5
There is a 1/8 chance to land three heads.
12.5%
The probability you'd get heads is still one half.
1/2 apex It does not matter what each prior flip's result was. Each flip has a probability of 0.5 heads or tails. Coins do not have "memory".
one fourth
It is 0.1042
The probability of 'heads' on any flip is 50% .
http://wiki.answers.com/Q/If_you_Flip_four_coins_at_once_what_is_probability_of_2_head_and_3_tail" The probability of flipping four coins and getting 2 heads and 3 tails is ZERO 2 heads and 3 tails requires flipping FIVE coins.
50%.
3/8
It is 0.5
The probability of the coin flip being heads or tails is 100%.