※ 引述《minimumi (米尼)》之铭言： : 41. : All of the stocks on the over-the-counter market are designated by either : a 4-letter or a 5-letter code that is created by using the 26 letters of : the alphabet. Which of the following gives the maximum number of different : stocks that can be designated with these codes? : (A) 2(26^5) : (B) 26(26^4) : (C) 27(26^4) : (D) 26(26^5) : (E) 27(26^5) : 81.If each term in the sum a1 + a2 + . . . + an is either 7 or 77 and the : sum equals 350, which of the following could be equal to n ? : (A) 38 : (B) 39 : (C) 40 : (D) 41 : (E) 42 : 想请问一下这两题在问什麽? 41. 其实你只要按部就班写算式即可 方法共有 26^4 + 26^5 = 26^4(1+26) = 27*26^4..............(C) 81. 是说这n项是由7或是77组成的 设共有x个7，y个77 则 7x + 77y = 350，化简得 x+11y=50 开始凑对有 (39,1)、(28,2)、(17,3)、(6,4)四种情况 得出 n 可能的项数有 40、30、20、10 对照答案选项得到唯一解............(C) --

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