从中任取5件
恰好取到0件次品的概率:(1-0.12)^5=0.88^5≈0.527732
恰好取到1件次品的概率:C(5,1)*0.12*(1-0.12)^4=5*0.12*0.88^4≈0.359817
恰好取到2件次品的概率:C(5,2)*0.12^2*(1-0.12)^3=10*0.12^2*0.88^3≈0.098132
恰好取到3件次品的概率:C(5,3)*0.12^3*(1-0.12)^2=10*0.12^3*0.88^2≈0.013382
恰好取到4件次品的概率:C(5,4)*0.12^4*(1-0.12)=5*0.12^4*0.88≈0.000912
恰好取到5件次品的概率:0.12^5≈0.000025