在现实生活中,我们的许多做法自己觉得很合理,实际上并没有理论根据,用我们所学的知识去衡量它,发现这些做法并无道理.这就要求我们在实际生活中解决问题时,一定要多问一问“为什么”. 例1 一件商品的售价为100元,由于热销提价20％出售;后来,由于季节原因销量越来越少,商家决定再降到100元出售,于是就打出了降价20％的牌子.这样做售价是 In the real life, many of our practices feel very reasonable. Actually, there is no theoretical basis. We use the knowledge we have learned to measure it. We find that these practices are not justified. This requires us to solve problems in real life. Be sure to ask “Why?”. Example 1 The price of a product is 100 yuan, which is due to the 20% selling price increase; later, due to seasonal reasons, the sales volume is getting less and less, the business has decided to lower it to 100. Yuan sold, so he hit a mark that reduced the price by 20%. The selling price is