刚开始看数学，各位帮帮忙

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8. Goldenrod and No Hope are in a horse race
with 6 contestants. How many different
arrangements of finishes are there if No Hope
always finishes before Goldenrod and if all of the
horses finish the race?
(A) 720
(B) 360
(C) 120
(D) 24
(E) 21
8. Start out by finding the total number of possible runner finish arrangements:
6´5´4´3´2´1 = 720 . Of those arrangements, half of them have No Hope beating
Goldenrod and the other half have Goldenrod winning. Since Goldenrod never comes in
before No Hope, the correct answer is 720 360
2
1 = ÷
ø
ö ç
è
æ or (B).
我的问题是参加比赛的到底是8匹马，还是6匹马
这道题怎么做？