Hi Geno, I was looking at what you did.
If you choose the non US prize winners like you did that is 16*15 then you are saying that there are 240 permutaions of those 2 places.
then 1 us person must be chosen. this can be done in 3 ways
now that US person can be 1st 2nd or 3rd So 3 ways
240*3*3 = 2160
You should not multiply this by 2 as all the possible permutations of the non US prize winners in relation to each other have already been accounted for.