本人文科生，请各位大侠详解！ 感激！
1. S=1-1/2+1/3-1/4+1/5-1/6+1/7-1/8+1/9-1/10与1/2比大小
解：S=1/2+(1/3-1/4)+(1/5-1/6)+(1/7-1/8)+(1/9-1/10)，其中括号内式子都大于0，所以1/2+大于0的数一定大于1/2
2. Y=x+1/x且0<x<10. 问the value of y与100比大小 答案是不确定
3. How
many positive 4-digit integers begin(on the left) with an odd digit and end
with an even digit? 答案是2500
看不懂题干
4. Which
of the following sets of numbers has the greatest standard deviation?
A. 2,3,4 B. 2.5, 3, 3.5 C. 1, 1.25, 1.5 D. -2, 0, 2 E. -20, 21, 21.5
答案是D，请问如何以最快速度判断出而不是算？
5. Workers
at Companies X and Y are paid the same base hourly rate. Workers at Company X
are paid 1.5 times the base hourly rate for each hour worked per week in excess
of the first 37, while the base hourly rate for each hour worked per week in
excess of the first 40. In a given week, how many hours must a Company X worker
work in order to receive the same pay as Company Y worker who works 46 hours? 答案是45
看不懂题目
6. Carol’s
age, in years, can be expressed by reversing the digits in her father’s age, in
years. The sum of the digits in each age is 10. 比较the positive difference between Carol’s age, in years,
and her father’s age, in years与36大小 答案是不确定
看不懂题目
7. A
developer has land that has x feet of lake frontage. The land is to be subdivided
into lots, each of which is to have either 80 feet or 100 feet of lake
frontage. If 1/9 of the lots are to have 80 feet of frontage each and the
remaining 40 lots are to have 100 feet of frontage each, what is the value of
x? 答案是不确定
看不懂题
8. What
is the least integer value of n such that (1/2^n)<0.001? 答案是10
怎做？