GMAT考试1-GMAT数学12月总结(二)

　　21. 在电话厅前排队，J前有13个人，问队伍总共多少人

　　 C后有16个人

　　 C前J后有3个人

　　My Answer: C

　　22. A circle inscribed in an equilateral triangle with side length = 10. What is the area of inscribed circle?

　　23. 机经的题目，W到X到Y到Z，三个送信人，一个速度70mile/分钟，一个速度80mile/分钟，一个速度100mile/分钟，总长750mile 求X到Y长，

　　答案是240

　　24. x = , if = , what is k?

　　My Answer: k = 200.

　　Old JJ:

　　X=10^100，有X^X= 10^K， 问K等于多少

　　remeo评价意见：10^102

　　25. If X is between 4497 and 4509, which number is closest to 23/?

　　My Answer: 3451

　　26. A right triangle is on top of a square. Square side is 100, right triangle sides are 60, 80 and 100 . How many bags of fertilizer to cover entire area?

　　My Answer: 7 bags.

　　27. Make a code of different letters from 10 letters . Whats the ratio of 5 letter code to 4 letter code?

　　My Answer: P/P = 6

　　28. r+s+t 是偶数么?

　　r+s是偶数

　　s+t是偶数

　　29. 有线段AC，AC上的一段AB正好是某圆柱体的体对角线，能求出AC的长么?

　　BC=2

　　AC有3/4长度在圆柱体内

　　30. 1998 sales increases x percent from 1997, 1999 sales decreases x percent from 1998, 1999 is 9 percent less than 1997. What is X?

　　My Answer: 30 percent

　　31. R=S/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? K\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\s current salary now is 94% more than that of 1967

　　 the index of 1967 is 100 and the index of now is 182

　　作者答案及思路：

　　33. A和B两个工程，A占2/3，B占余下的，B要花的时间是7/5 as much as A 问B花的时间占总共时间多少，

　　我的答案好象是7/17

　　34. y=1/), What is x defined as?

　　I 4

　　II 6

　　III 8

　　35. 有一个连续数的集合，问7是否在这个集合里面

　　a) -7在里面

　　b) 9在里面

　　36. A rectangle ABCD area is 84, point E is on line AB and AE/EB = 4/3, point F is on line DC, what is area of triangle AFE?

　　37.一个圆圆心在，一直线y=x，k同时在圆上和线上，问k坐标：

　　答案：

　　38.JJ本月题99到301间的偶数的和

　　答案：20200

　　方法：99到301间的偶数的和=100到300间的偶数的和，等差数列求和=N/2= 101/2=20200

　　39.JJ本月题 / = X ^ + X ^ + +1, 且7^8= 一个具体的数值C，问7^9=?

　　答案：

　　方法：假设X=7, N=9, 那么7^9 / 6 = 7^8 + 7^7+7^6++1

　　假设X=7, N=8, 那么7^8 / 6 = 7^7+7^6++1

　　因为 7^8=C，所以 7^7+7^6++1 = C/6

　　综合以上=〉 7^9 = 6=7C/6

　　说明：具体公式可能略有偏差，但方法是这样的，请大家掌握此类方法，勿记答案。

　　40.ABCDEFG中随便取3个，但是AB不能在一起，问可能性?

　　答案：C-5