The purchase price of a shoe is 45 yuan, and the selling price of a pair of shoes is 30 yuan. Then the buying price and selling price of a pair of shoes are 90 yuan and 60 yuan respectively. If you buy 90 pairs of shoes and sell 60 pairs of shoes, even if the money is not fake, 30 yuan has already lost money, but 100 yuan is fake, which is equivalent to another loss of 100 yuan and a loss of 100 pieces 10 30 = 65438+.