請問一下這3題數學 167. If x is positive, which of the following could be the correct ordering of : 1/x,2^x, and x^2 ? :(a) x^2 < 2^x < 1/x :(b) x^2 < 1/x < 2^x :(c) 2^x < x^2 <1/x 答案只有a&b 我知道這要代數字進去 但要怎要帶比較快? 188. Last month 15 homes were sold in Town X. The average (arithmetic mean) sale price of the homes was $150,000 and the median sale price was $130,000. Which of the following statements must be true? I.At least one of the homes was sold for more than 165,000 II.At least one of the homes was sold for more than 130,000 and less than 150,000 III. At least one of the homes was sold for less than 130,000 (A)I only (B)II only (C)III only (D)I and II (E)I and III 答案是A 190. Pumps A, B, and C operate at their respective constant rates. Pumps A and B, operating simultaneously,can fill a certain tank in 6/5 hours; pumps A and C, operating simultaneously, can fill the tank in 3/2 hours; and pumps B and C, operating simultaneously, can fill the tank in 2 hours. How many hours does it take pumps A, B, and C, operating simultaneously, to fill the tank? 答案是1 不好意思 問題有點多 謝謝 麻煩一下 --

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