作者young99 (结束即是开始)
看板GMAT
标题[机经] 计量一问
时间Sun Oct 26 22:24:50 2008
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?
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
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