(1) 2.5x0.7x0.7x0.7=0.8575,为85.75%(拆神2)设原价为a元每件,那么原价销售为100a元,按降价销售为10x2.5ax0.7+40x2.5ax0.7x0.7+50x2.5ax0.7x0.7x0.7=109.375a新雀答方案旅岁亏赢利多