※ 引述《young99 (结束即是开始)》之铭言： : 1. Each of 200electrical switches controls a separate light bulb. How many of : the switches are in the OFF position? : (1) 40 percent of the bulbs are glowing. : (2) 5 percent of the bulbs are burnt out. : 答:E， 我知道单独(1)，(2)皆错，但合并考虑时，从(2)的条件可以得知坏掉的数目 : (10)，那剩下的皆是好的(190)，再加上(1)的条件应该可得知OFF的数目了吧? : 还是还有其他可能性? burnt out 的5% 没办法确定是ON or OFF 所以答案 E : 2.Two tanks, X and Y, are filled to capacity with jet fuel. Tank X holds 600 : gallons more than tank Y. If 100 gallons of fuel were to be pumped from : each tank, tank X would then contain 3 times as much fuel as tank Y. What is : the total number of gallons of fuel in the two full tanks? : (A)1400 : (B)1200 : (C)1000 : (D)900 : (E)800 : 答:A，这一题我看很久，还是不知上下给的条件有何关系? : 第一个条件: X = 600+Y : 第二个条件: X = 3Y ; X + Y = 100。 : 请问如何解出1400这个数字啊? : 谢谢大家 条件1. X = 600 + Y 条件2. X-100 = 3(Y-100) 两式联立 Y = 400 ; X = 1000 X + Y = 1400 以上个人浅见 大家讨论讨论 谢谢 --

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