=91÷65%
=140(件)
2、1-20%-[(1-20%)x50 %]
=80%-40%
=40%
3、75%+1/2-1
=75%+50%-100%
=25%
4.上中百貨大樓:(5-1)x60=240(人民幣)
潘潘超市:5x60x80%=240元
買五個和買兩個壹樣便宜!