*31*

For any given coin flip, the probability of getting “heads” is 1/2 or 0.5.

To find the probability of at least one head during a certain number of coin flips, you can use the following formula:

P(At least one head) = 1 – 0.5^{n}

where:

**n**: Total number of flips

For example, suppose we flip a coin 2 times.

The probability of getting at least one head during these 3 flips is:

- P(At least one head) = 1 – 0.5
^{n} - P(At least one head) = 1 – 0.5
^{3} - P(At least one head) = 1 – 0.125
- P(At least one head) =
**0.875**

This answer makes sense if we list out every possible outcome for 2 coin flips with “T” representing tails and “H” representing heads:

- TTT
- TTH
- THH
- THT
- HHH
- HHT
- HTH
- HTT

Notice that at least one head (H) appears in 7 out of 8 possible outcomes, which is equal to 7/8 = **0.875**.

Or suppose we flip a coin 5 times.

The probability of getting at least one head during these 5 flips is:

- P(At least one head) = 1 – 0.5
^{n} - P(At least one head) = 1 – 0.5
^{5} - P(At least one head) = 1 – 0.25
- P(At least one head) =
**0.96875**

The following table shows the probability of getting at least one head during various amounts of coin flips:

Notice that the higher number of coin flips, the higher the probability of getting at least one head.

This should make sense considering the fact that we should have a higher probability of eventually seeing a head appear if we keep flipping the coin more times.

**Additional Resources**

The following tutorials explain how to perform other common calculations related to probabilities:

How to Find the Probability of “At Least One” Success

How to Find the Probability of “At Least Two” Successes

How to Find the Probability of A and B

How to Find the Probability of A or B