2. a code of a sequence of different letters from ABCDEFGHIJ, ten letters, the ratio of the number of five-letter code to the number of four-letter code? (十选五全排列除以十选四全排列：6：1)
3. 6^3*8^5=2^v*3^w, v+w=? (21)
4. a line passes through the point (n,-1), whether the slope of the line greater than zero? (1) the line passes through the original point(2)the line passes through the point (1, 3n-1)(这里可能不是很准确，但不影响解题) (my key: C )
5. three people carry messages in the same amount of time at respective speed, A carries from place W to X at the speed of 100 miles per minute, B from X to Y at 80 miles per minute, C from Y to Z at 70 miles per minute. the points WXYZ are on a line and at the certain sequence, the distance from W to Z is 750 miles. What is the distance from X to Y? (240miles)
6. Two different pipes fill the same tank. X fills 1/2 of the volumn of the tank for 3 hours, Y fill 2/3 of it for 6 hours. If the two pipes fill the tank simutaneously with respective speed, how long will the tank be filled? (3.6 hours)
7. a triangle with three sides of x+1, 2x-1 and x, (前两个不是很确定，了解意思即可)， 前两个是腰，题中给出两个底角相等，求底边x=?
8. in a sequence, the Nth item is dicribed as Xn=1/n-1/(n+1), what is the sum of the first 100 items of the sequence? (100/101)
9. in an economics class, what is the ratio of the number of business major to the number of non-business major?(1)the number of business major is 4 more than the number of non-business major. (2) 5/9 of the class students are business major (my key: B)
10. the present sales tax for automotives is increased by 0.5% from the original sales tax which is 6%. How much will a person be charged more than the amount of before for a $12,000 automotive as the consequence of the increased tax rate? (60)
11. R=S(100)/P, in the equation, R is the real salary of a person, S is the current salary, and P is a kind of index. Whether the person K's real salary now is more than the real salary of 1967? (1)K's current salary now is 94% more than that of 1967 (2) the index of 1967 is 100 and the index of now is 182 (C)
12. r, s ,t are positive integers, is the sum of r, t, s even? (1) r+t is even (2) s+t is even (E)
13. r,s,t are positive integers. Is t/s^2 an integer? (1) t/(rs) is an integer. (2) r/s is an integer (C)
14. a, b are nonnegative numbers and (a-b)/(a+b)=1/2, which one of the following must be true? (Choice C: a>b)
15. Is there any change of the percentage of the number of workers …….？ (后面记不太请了， 但不影响理解) （1）the percent of workers of … in 1991 is 67% (2) the percent of number of workers of … in 1997 is 73％ （其中数字不准，可是这道题关键的叙述就是这样，如有不妥请补充，但这道题是我唯一一道不确定的，紧供大家讨论）
