Question

抛掷3枚硬币,求下列事件的概率1)A=｛有1枚正面向上｝2)B=｛有2枚正面向上｝3)C=｛全部正面向上｝

Answer 1

P(A)=C(3,1)*(1/2)*(1/2)^2=3/8

P(B)=C(3,2)*(1/2)^2*(1/2)=3/8

P(C)=C(3,3)*(1/2)^3=1/8