Since we are doing flips of a coin, we can agree that each flip is independent of all of the other.
The probability that a coin lands on heads is 1/2, just as the probability that a coin lands on tails is 1/2.
Since each event is independent, we take the probabilities of the events and multiply them together to get the overall probability:
P(H) = 1/2
P(T) = 1/2
So:
P(H, T, H, H, H) = (1/2) x (1/2) x (1/2) x (1/2) x (1/2) = 1/32
The overall probability is 1/32.