1.For a finite sequence of nonzero numbers, the number of variations in sign is defined as the number of pairs of consecutive of the sequence for which the product of the two consecutive terms is negative. What is the number of variations in sign for the sequence 1、-3、2、5、-4、-6？
A one B two C three D four E five
答案是C 原谅我连题目都看不懂~~~~(>_<)~~~~
2.The residents of town X participated in a survey to determine the number of hours per week each resident spent watching TV. The distribution of the results of the survey had a mean of 21 hours and a standard deviation of 6 hours. The number of hours that Pat, a resident of town X, watched TV last week between 1 and 2 standard deviation below the mean, which of the following could be the number of hours that Pat watched TV last week? A 30 B 20 C 18 D 12 E 6
答案选D 求解？
3.At least 100 students at a certain high school study Japanese. If 4% of the students at the school who study French also study Japanese, da more students at the school study French than Japanese?
(1) 16 students at the school study both French and J apanese (2) 10% of the students at the school who study Japanese also study French
3.At least 100 students at a certain high school study Japanese. If 4% of the students at the school who study French also study Japanese, da more students at the school study French than Japanese?
(1) 16 students at the school study both French and J apanese (2) 10% of the students at the school who study Japanese also study French
京公网安备11010202008513号 京ICP证101109号 京ICP备12012021号
发表于 2010-12-1 00:35:58
收藏
收藏
