SAT数学Problem Solving练习题（1）

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以下是易伯华SAT频道为大家整理了SAT数学Problem Solving练习题(1)，供考生们参考，以下是详细内容。

Question #1: If a · b = 18 and a / b = 2, a 0, b 0 then:

(a) a = 18 and b = 1

(b) a = 9 and b = 2

(c) a = 18 and b = 9

(d) a = 6 and b = 3

(e) a = 6 and b = 6

Answer: a / b = 2

a = 2·b.

a·b = (2· b)· b

a·b = 2· b 2.

2· b 2 = 18

b 2 = 9,

b = 3 because b 0,

a = 2· b

a = 6.

Question #2: The ratio of the radii of two circles is r1/r2 = 6. What is the

ratio of the perimeters P1/P2 and the ratio of the areas of the two circles

A1/A2?

(a) perimeter ratio = 1/6, area ratio = 36

(b) perimeter ratio = 36, area ratio = 6

(c) perimeter ratio = 6, area ratio = 36

(d) perimeter ratio = 1/8, area ratio = 8

(e) perimeter ratio = 1/6, area ratio = 6

Answer: r1 / r2 = 6;

Perimeter1 / Perimeter2 = (2· ¶· r1)/(2· ¶· r2) = r1/ r2 = 6

Area1 / Area2 = (¶· r12)/ (¶· r22) = r12 / r22 = 36