11 choose 5

解答

11 C 5

462

求解步骤

= \frac{n !}{r ! ( n - r ) !}

代入

n = 11, r = 5

= \frac{11 !}{5 ! ( 11 - 5 ) !}

\frac{11 !}{5 ! ( 11 - 5 ) !} = 462

= 462

23 C 4

m e d ian 12.5, 12.7, 14.9, 11.3, 11.7, 10.9

r an g e 8, 4, 9, 2, 8, 2, 6, 2, 2, 4

v a r ian ce 340, 75, 123, 259, 151

a r i t hm e t i c m e an 3, 3, 3, 3, 0, 1, 1, 6, 6, 7