5 over 2, i.e. the number of combinations of 2 elements from 5. To understand this you need to study a little bit of combinatorics (how to count combinations): you might want to start from the lectures on combinatorics at statlect.com.
The probability of flipping a coin 3 times and getting 3 heads is 1/2
If the coin is not biased, the answer is 0.375
25%
6.25%
You still still have a 1:2 chance of getting heads regardless of the times you flip.
the probability of getting heads-heads-heads if you toss a coin three times is 1 out of 9.
The probability of flipping a coin 3 times and getting 3 heads is 1/2
For 3 coin flips: 87% chance of getting heads at least once 25% chance of getting heads twice 13% chance of getting heads all three times
If the coin is not biased, the answer is 0.375
25%
1/2
6.25%
The probability of getting heads on a single coin flip is 0.5. To find the probability of getting heads four times in a row, you multiply the probability of getting heads for each flip: (0.5 \times 0.5 \times 0.5 \times 0.5 = 0.5^4 = 0.0625). Thus, the probability of flipping heads four times in a row is 6.25%.
About a 1 in 16 chance of getting a coin to land on heads 4 times in a row.
You still still have a 1:2 chance of getting heads regardless of the times you flip.
There are 8 permutations of flipping a coin 3 times, or of flipping 3 coins one time. They are, with the permutations of two heads bolded...TTTTTHTHTTHHHTTHTHHHTHHH... thus, the probability of flipping a coin 3 times and getting 2 heads is 3 in 8, or 0.375.
The odds of getting heads on a single coin flip are 1 in 2. To find the probability of getting three heads in a row, you multiply the probability of getting heads on each flip: ( \frac{1}{2} \times \frac{1}{2} \times \frac{1}{2} = \frac{1}{8} ). Thus, the odds of getting three heads in a row when flipping a coin are 1 in 8.