1. The people eating in a certain cafeteria are either faculty members or students, and the number of faculty members is 15 percent of the total number of people in the cafeteria. After some of the students leave, the total number of persons remaining in the cafeteria is 50 percent of the original total. The number of students who left is what fractional part of the original number of students? A.17/20 B.10/17 C.1/2 D.1/4 E.7/20 正确答案是:B 我做的是C,请帮忙告诉我怎么做的? 2. The enrollments at College X and College Y both grew by 8 percent from 1980 to 1985. If the enrollment at College X grew by 800 and the enrollment at College Y grew by 840, the enrollment at College Y was how much greater than the enrollment at College X in 1985? A.400 B.460 C.500 D.540 E.580 正确答案:D 我做的是C,请帮忙告诉我怎么做的?
3. A figure that can be folded over along a straight line so that the result is two equal halves which are then lying on top of one another with no overlap is said to have a line of symmetry. Which of the following figures has only one line of symmetry? A. square B. circle C. equilateral triangle D. isosceles triangle E. rectangle 正确答案是:D 题目没看懂,请帮忙翻译一下……谢谢了啊……
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