
Answer:
1320 ways
Step-by-step explanation:
First we have 4 americans and 11 non-americans, so for one medal, the number of possibilities for americans is 4.
Then, for a second medal, we want a non-american, so there are 11 possibilities.
For the third medal, we have only 10 possibilities, as one non-american has already got the second medal.
As the american can win any of the three positions, we also need to multiply the probabilities by a combination of 3 choose 1: C(3,1) = 3
So the number of ways that exactly one american wins a medal is:
3 * 4 * 11 * 10 = 1320 ways