作者catspace (柏拉图的永恒...)
看板GMAT
标题Re: [问题] 问几题数学题
时间Wed Dec 31 21:12:43 2008
※ 引述《chihkai (就这样毕业了....)》之铭言：
: 因为写到了两题不太懂得数学 上来请教各位了
: 1.The rate of a certain chemical reaction is directly proportional to the
: square of the concentration of chemical A present and inversely proportional
: to the concentration of chemical B present. If the concentration of chemical
: B is increased by 100 percent, which of the following is closest to the
: percent change in the concentration of chemical A required to keep the
: reaction rate unchanged ?
: (A)100% decrease (B)50% decrease (C)40% decrease (D)40% increase
: (E)50% increase
: ANS:(D)
请参阅2790篇解说
: 2.For every positive even integer n the function h(n) is defined to be the
: product of all the even integers from 2 to n, inclusive. If p is the
: smallest prime factor of h(100)+1, then p is ??
: (A)between 2 to 10 (B)between 10 to 20 (C)between 20 to 30
: (D)between 30 to 40 (E)greater than 40
: ANS:(E)
令 A = h(100) + 1 = 2*4*6*8*...*100 + 1
所有介於2~100间的质数都不可能是A的因数
故此质数必大於100
也只有选(E)了
: 以上两题 麻烦各位了 感谢
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