标题: 三道题目求解 谢谢各位帮忙 二月一日北美考试 [打印本页] 作者: woshishizhan 时间: 2012-1-19 01:02 标题: 三道题目求解 谢谢各位帮忙 二月一日北美考试 If X^4+Y^4=100, then the greatest possible value of X is between 0-3 3-6 6-9 9-12 12-15 A company plans to assign identification numbers to its employees. Each number is to consist of four different digits from 0 to 9, inclusive, except that the first digit can't be 0. How many different identification numbers are possible? 3024 4536 5040 9000 10,000 A certain city with a population of 132000 is to be divided into 11 voting districts, and no district is to have a population that is more than 10 percent greater than the population of any other district, what is the minimum possible population that the least populated district could have? 10700 10900 10900 11000 11100作者: zhangyupeng120 时间: 2012-1-19 02:40
楼主你好。第一题说求X最大值，极端情况可以把Y看做0.就是求X四次方等于100的最大情况。试数可以发现，4的4次方是16乘16一定是大于100的，3的四次方就是81，在一百以内，所以X最大情况就是3和4之间，也就是选项中的3到6.