The probability to get heads once is 1/2 as the coin is fair
The probability to get heads twice is 1/2x1/2
The probability to get heads three times is 1/2x1/2x1/2
The probability to get tails once is 1/2
The probability to get tails 5 times is (1/2)5
So the probability to get 3 heads when the coin is tossed 8 times is (1/2)3(1/2)5=(1/2)8 = 1/256
If you read carefully you'll understand that 3 heads and 5 tails has the same probability than any other outcome = 1/256
As the coin is fair, each side has the same probability to appear
So the probability to get 3 heads and 5 tails is the same as getting for instance 8 heads or 8 tails or 1 tails and 7 heads, and so on
3 out of 8
1/36
The opposite of getting at most two heads is getting three heads. The probability of getting three heads is (1/2)^2, which is 1/8. The probability of getting at most two heads is then 1 - 1/8 which is 7/8.
3/8ths
1/2
3 out of 8
Since a coin has two sides and it was tossed 5 times, there are 32 possible combinations of results. The probability of getting heads three times in 5 tries is 10/32. This is 5/16.
The probability of tossing two heads in two coins is 0.25.
1/36
The opposite of getting at most two heads is getting three heads. The probability of getting three heads is (1/2)^2, which is 1/8. The probability of getting at most two heads is then 1 - 1/8 which is 7/8.
3/8ths
1/2
It is 1/16.
The mathematical probability of getting heads is 0.5. 70 heads out of 100 tosses represents a probability of 0.7 which is 40% larger.
The probability of getting exactly eight heads when tossing 10 coins once can be found using the binomial probability formula. Assuming a fair coin, the probability of getting a heads is 1/2. Plugging in the numbers, the probability of getting exactly eight heads is (10 choose 8) * (1/2)^8 * (1/2)^2 = 45/1024, which is approximately 0.04395.
The answer depends on how many times the coin is tossed. The probability is zero if the coin is tossed only once! Making some assumptions and rewording your question as "If I toss a fair coin twice, what is the probability it comes up heads both times" then the probability of it being heads on any given toss is 0.5, and the probability of it being heads on both tosses is 0.5 x 0.5 = 0.25. If you toss it three times and want to know what the probability of it being heads exactly twice is, then the calculation is more complicated, but it comes out to 0.375.
The probability is 0.375