(1)成活两颗的概率 =sigma(一种不成活其它两种成活）=0.4*0.5*0.4+0.5*0.6*0.4+0.6*0.6*0.5=0.38(2)成活一棵的概率=sigma(一种成活其他不成活)=0.6*0.5*0.6+0.5*0.4*0.6+0.4*0.5*0.4=0.38(3)全都成活的概率 =0.6*0.5...