The last math problem in Xiaoshengchu, Heping District, Tianjin in 2009,
Dafeng supermarket bags a batch of bulk rice, and each bag is required to have the same weight. Take out 40% of the total rice for the first time, and fill 30 bags with the remaining15 kg; The second time, [b] put all the remaining [/b] rice in 50 bags (each bag has the same weight as the first bag). How many kilograms is this batch of rice?
The expression of this question is very imprecise, and several answers can be drawn. What do you think the correct answer should be?
The first type: "all rice left" can be understood as the total proportion/equation of 60% of the total: (0.4x-15)/30 = 0.6x/50.
The second type: "all remaining rice" can be understood as the total proportion of unfinished 15kg/equation: (0.4x-15)/30 =15/50.
The third type: "all rice left" can be the sum of two ratios/equations: (0.4x-15)/30 = (0.6x+15)/50.
The answers to the above three different understandings are also different: 375, 60 and 600 kilograms.
However, the Education Bureau said that only 600 was correct, and of course other answers could not be admitted, which indicated that it was wrong. However, how many children have been hurt in this way, 6 points, so that parents who have no power or influence and go to school solely on the basis of their children's grades will hit the wall.