单选题 In 1995, approximately how many million people were on the Zone Diet?
  • A. 12.2
  • B. 17.0
  • C. 23.0
  • D. 24.3
  • E. 35.7
【正确答案】 C
【答案解析】In 1995 the total number of dieters was 135 million. 17% of these people were on the Zone Diet: 0.17×135=22.95, or approximately 23 million people.
单选题 What is the ratio of the number of people on the Slim Fast diet in 1995 to the number of people on the Mediterranean diet in 2000? A. B. C. D. E.
【正确答案】 D
【答案解析】In 1995, 3% of 135 million people were on the Slim Fast diet: 0.03×135=4.05. In 2000, 6% of 210 million people were on the Mediterranean diet: 0.06×210=12.6. So the ratio is 4.05 : 12.6, or 405: 1,260. This reduces to 9:28 or [*]
单选题 Approximately what is the percent increase in the number of Master Cleanse dieters from 1995 to 2000?
  • A. 200%
  • B. 157%
  • C. 189%
  • D. 187%
  • E. 129%
【正确答案】 C
【答案解析】In 1995, 0.07×135, or 9.45 million people were on the Master Cleanse diet. In 2000, 0.13 × 210, or 27.3 million people were on it. The difference between the two numbers is 17.85. So the fraction is the difference over the original, or [*], which simplifies to 1.88888 or 1.89.
单选题 What is the approximate measure of the central angle representing Atkins dieters in 1995?
  • A. 9°
  • B. 15°
  • C. 32°
  • D. 91°
  • E. 324°
【正确答案】 C
【答案解析】According to the circle graph, Atkins dieters represent 9% of the total number of dieters in 1995. There are 360° in a circle, so the approximate measure of the central angle representing Atkins dieters in 1995 is 360(0.09) = 32.4, which rounds to 32.
单选题 If A=(x-y)-z and B=x-(y-z), then A-B=
  • A. -2z
  • B. -2y
  • C. 0
  • D. 2z
  • E. 2y
【正确答案】 A
【答案解析】To solve this problem, first set it up: (x-y)-z-(x-(y-z)). Now simply perform the subtraction (pay attention to the negative signs!) to get -2z.
填空题 If -7＜x＜5 and -3＜y＜4, what is the greatest possible value of (y-x)(x+y)?
单选题 A square is inscribed in a circle. If the area of the inscribed square is 50, what is the area of the circle? A. 5π B.
【正确答案】 D
【答案解析】If the area of the square is 50, then one side of the square is [*] or [*]. The diagonal of an inscribed square is equal to the diameter of the circle. The diagonal creates 2 isosceles right triangles.
Use the Pythagorean Theorem: [*]. Simplify the equation and you get c=10. If the diameter is 10, then the radius is 5. Since the area of a circle is πr2, the area of this circle is 25π.