When you flip a fair coin, there are 2 possible outcomes: heads (H) or tails (T). Each outcome is equally likely, so the probability of getting heads on a single coin flip is 1/2.

To find the probability of getting all heads when flipping four fair coins, you need to calculate the probability of getting heads on each coin flip and then multiply these probabilities together because each coin flip is independent of the others.

P(All Heads) = P(Head on Coin 1) * P(Head on Coin 2) * P(Head on Coin 3) * P(Head on Coin 4)

Since each coin flip has a 1/2 probability of landing heads:

P(All Heads) = (1/2) * (1/2) * (1/2) * (1/2) = (1/16)

So, the probability of getting all heads when flipping four fair coins is 1/16. Therefore, the answer is 1/16