If N is the average (arithmetic mean) of five numbers, which of the following must be true? I. At least one of the five numbers is greater than or equal to N. II. At least one of the five numbers is less than or equal to N. III. At least two of the five numbers are greater than or equal to N. (A) I only (B) II only (C) I and II only (D) I and III only (E) I, II, and III Ans:(C) For which of the following pairs of integers is the least common multiple of the integers minus their greatest common divisor the greatest? (A) 3,12 (B) 5,6 (C) 10,20 (D) 11,12 (E) 15,30 Ans:(D) Circles R,S, and T are in the same plane, have a common center, and have radii r,s, and r+s, respectively, where 0<r<s. Column A The area of the region whose boundary consists of circles R and T Column B 拍s^2 (抱歉不會打圓周率) Ans: (A) 謝謝! --

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