Answer:
1. 2730
2. 440
Step-by-step explanation:
Given that we have 15 skaters.
Number of Americans = 4
Number of other skaters = 11
1. Out of these 15, 3 medals are to be awarded.
Number of ways = ?
Number of possible ways for the first medal = 15
Number of possible ways for the second medal = 14
Number of possible ways for the third medal = 13
Required Number of ways = [tex]15 \times 14 \times 13[/tex] = 2730
2. Out of 15 medals, exactly 1 American wins medal and other 2 medals go to others. Number of ways = ?
Number of possible ways that one medal goes to an American = 4 (i.e. out of 4 Americans, one of them wins a medal)
Number of ways that other 2 medals go to others = [tex]11 \times 10[/tex] (others are 11)
Required Number of ways = [tex]4 \times 11 \times 10[/tex] = 440
So, the answers are:
1. 2730
2. 440