甲乙胜 丙负的概率:0.4*0.5*0.4=0.08
甲丙胜 乙负的概率:0.4*0.5*0.6=0.12
甲负 乙丙胜的概率:0.6*0.5*0.6=0.18
甲乙丙都胜的概率:0.4*0.5*0.6=0.12
所以红队至少两名队员获胜的概率为:0.08+0.12+0.18+0.12=0.5
ξ=0 p=0.6*0.5*0.4=0.12
ξ=1 p=0.4*0.5*0.4+0.6*0.5*0.4+0.6*0.5*0.6=0.38
ξ=2 p=0.08+0.12+0.18=0.38
ξ=3 p=0.12
故数学期望为Eξ=0*0.12+1*0.38+2*0.38+3*0.12=1.5