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假设法是培养学生思维的一种重要方法。在解答竞赛题时,一般采用单项假设.但步骤复杂,模式单调。惹人烦恼。如能抓住题型特点。巧用多项假设,不但优化解题策略,而且解答迅速,计算简便。下举一例说明之。例已知甲校学生数是乙校学生数的40％,甲校女生数是甲校学生数的30％,乙校男生数是乙校学生数的的42％。那么两校女生总数占两校学生总数的百分比等于____。(93年全国小学数学奥林匹
Hypothesis method is an important way to train students' thinking. In the race to answer questions, the general assumption of a single, but the steps are complex, the model monotonous. Causing trouble. If you can grasp the characteristics of the questions. Clever use of a number of assumptions, not only optimize the problem-solving strategy, but also quick answers, easy to calculate. Give an example to explain. For example, it is known that the number of students in a school is 40% of the number of students in a school, the number of girls in a school is 30% of the number of students in a school, and the number of male students in the second school is 42% of the number of students in the second school. Then the total number of girls in both schools accounting for the total number of students in both schools is equal to ____. (93 National Primary School Mathematical Olympiad