GMAT数学精华题型解析(3)

A construction company was paid a total of $500,000 for a construction project. The company's only costs for the project were for labor and materials. Was the company's profit for the project greater than $150,000 ?

(1) The company's total cost was three times its cost for materials.

(2)The company's profit was greater than its cost for labor.

【答案】C

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If wx = y, what is the value of xy ?

(1) wx2 = 16

(2) y = 4

【答案】A

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Are at least 10 percent of the people in Country X who are 65 years old or older employed?

(1) In Country X, 11.3 percent of the population is 65 years old or older.

(2) In Country X, of the population 65 years old or older, 20 percent of the men and 10 percent of the women are employed.(陷阱) 【答案】B

In the figure above, what is the ratio

(1) The perimeter of rectangle KLMN is 30 meters.

(2) The three small rectangles have the same dimensions.是指面积相同，但同时也是指长宽都相同

【答案】B

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At a dinner party, 5 people are to be seated around a circular table. Two seating arrangements are considered different only when the positions of the people are different relative to each other. What is the total number of different possible seating arrangements for the group?

(A) 5

(B) 10

(C) 24

(D) 32

(E) 120

【答案】C

【思路】

若為一直線排法為5!

但此題目為圓形

五個人排圈圈...

ABCDE

BCDEA

CDEAB

DEABC

EABCD

都是一樣故排圈圈時就是5!/5=4!

除以五是為了消除每次相鄰位置改變時都會有重複的情況

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If x is a negative integer, which of the following expressions has the LEAST value?

【答案】D