3/5Ⅹ0.8+0.6ⅹ1/5=0.6x0.8+0.6㐅0.2=(0.8+0.2)ⅹ0.6=1x0.6=0.6
3/5×0.8+0.6×1/5=0.6×0.8+0.6×0.2=0.6×(0.8+0.2)=0.6×1=0.6