题目内容
已知随机变量ξ~B(n,p),且Eξ=12,Dξ=2.4,则n与p的值分别是
A.15与0.8
B.16与0.8
C.20与0.4
D.12与0.6
已知随机变量X~B(n,0.8),D(X)=1.6,则n的值是
A.8 B.10 C.12 D.14