An unbiased coin is tossed three times. Find the probability of the given event.

I have many similar questions to this and need to figure out how to solve to produce an answer.

An unbiased coin is tossed three times. Find the probability of the given event. (Enter your answer to five decimal places.)

The coin lands heads exactly once.

I'm probably doing this wrong but i thought I would give it a shot
h h h
h h t
h t t YES
h t h
t t t
t h t YES
t h h
t t h YES

3/8

0.375
37.50000%

Binomial Distribution!

Let X be the number of heads that the coin shows.

n = 3

p = 0.5, q = 1 - 0.5 = 0.5

P(X = 1) =

(3)
(1)*(0.5^1)*(0.5^2) = 3*0.5*0.25 = 0.375