The answer to the first question is 0.5. The answer to the second is not possible to work out.
It is 1/2.
The probability of flipping three tails with three coins is (1 in 2)3 or 1 in 8 or 0.125.
If they are fair coins, the probability is 0.25
For a normal coin, it is 0.5.
The probabilty of you flipping 3 coins and getting all heads or tails is 0.125 or 1/8.
The probability of getting all tails is 1/25 = 1/32
The probability of a fair coin landing on tails is 0.5. The probability of 4 tails is .5*5*.5*.5 = 0.0625.
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.
the probabiluty of two coins landing on tails is 1/2 x 1/2 = 1/4, or one chance in four
It is 1/2.
The probability of 2 coins both landing on heads or both landing on tails is 1/2 because there are 4 possible outcomes. Head, head. Head, tails. Tails, tails. Tails, heads. Tails, heads is different from heads, tails for reasons I am unsure of.
The probability of getting all tails when you flip 4 fair coins 1 time is:P(4 tails) = (1/2)4 = 1/16 = 0.0625 = 6.25%