一些逻辑问题的分析

Christianyang

师姐，你火了。。。

aomeisoft7

The only physical factor preventing a human journey to Mars has been weight. Carrying enough fuel to propel a conventional spacecraft to Mars and back would make even the lightest craft too heavy to be launched from Earth. A device has recently been invented, however, that allows an otherwise conventional spacecraft to refill the craft’s fuel tanks with fuel manufactured from the Martian atmosphere for the return trip. Therefore, it is possible for people to go to Mars in a spacecraft that carries this device and then return.

Which one of the following is an assumption on which the argument depends?

A.    The amount of fuel needed for a spacecraft to return from Mars is the same as the amount of fuel needed to travel from Earth to Mars.
B.    The fuel manufactured from the Martian atmosphere would not differ in composition from the fuel used to travel to Mars.
C.    The device for manufacturing fuel from the Martian atmosphere would not take up any of the spaceship crew’s living space.
D.    A conventional spacecraft equipped with the device would not be appreciably more expensive to construct than current spacecraft typically are.
E.    The device for manufacturing fuel for the return to Earth weighs less than the tanks of fuel that a conventional spacecraft would otherwise need to carry from Earth for the return trip.

这个A中也提到了重量，我觉得这也算是一个必须的假设。。因为如果去和回来fuel的量不一样的话，有可能会导致飞船飞不回来不是吗？求帮忙解答一下~多谢了！答案是E。

-- by 会员 songhanxiao (2010/9/24 18:39:25)

此题求假设
A.    The amount of fuel needed for a spacecraft to return from Mars is the same as the amount of fuel needed to travel from Earth to Mars.
开始我一看到这个选项时就觉得挺对的，但是看到E对比出E更好
A这里的缺陷我觉得是 the same as  正确的假设应该是：less amount
没有说必须要求来回花的fuel一样，如果回来时消耗的fuel 比去的时候更少，也可以满足结论啊！那么这个假设就不对


E这个选项是对的， 发明device的原因就是因为以前带fuel升天很重，如果device比fuel还重，那更飞不起来了

aomeisoft7

师姐，你火了。。。

-- by 会员 Christianyang (2010/9/24 20:02:41)

哈哈，要更火

bdsjb116

回答下我的问题吧

Which of the following most logically completes the argument?

Researchers recently asked dozens of shoppers, chosen at random coming out of a FoodBasket supermarket, what they had purchased.The prices of the very same items at the nearest ShopperKing supermarket were totaled and compared with the FoodBasket total.The ShopperKing totals averaged five percent higher than the FoodBasket totals.Nevertheless, this result does not necessarily show that shoppers at ShopperKing would save money overall by shopping at FoodBasket instead, since __________.

A. shoppers who shop regularly at a given supermarket generally choose that store for the low prices offered on the items that they purchase most often

B. for shoppers with more than 20 items, the ShopperKing totals averaged more than five percent higher than the FoodBasket totals

C. many shoppers consider factors other than price in choosing the supermarket at which they shop most regularly

D. there is little variation from month to month in the overall quantity of purchases made at supermarkets by a given shopper

E. none of the people who conducted the research were employees of the FoodBasket supermarket

E质疑样本取得的可信程度啊，也是WEAKEN啊

-- by 会员 syq819 (2010/9/24 15:00:44)

S店 商品平均价格 高于 F店 商品平均价格
但是 S店顾客 改去 F店购物 却不能省钱
求 解释


A. shoppers who shop regularly at a given supermarket generally choose that store for the low prices offered on the items that they purchase most often
顾客 去 经常买的商品 相对低价的店
比如 商品A B C D ， S店 A B相对便宜， C D 相对贵
那么经常买A B的人就会去S店，经常买C D的人就会去F店
所以S店顾客去F店买A B ，会花费更多的钱


E. none of the people who conducted the research were employees of the FoodBasket supermarket
没有一个负责调查的人 是F店的雇员。 无关
people who conducted the research 是 负责调查的人， 而不是 被调查的样本
题目条件已指出：Researchers recently asked dozens of shoppers, chosen at random coming out of a FoodBasket supermarket
researchers 是 random 随机 的，所以样本可信

-- by 会员 aomeisoft7 (2010/9/24 15:54:52)

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随便说一下，我当时做的时候选的是C。后来发现答案是A就回去看了下题干然后发现问题其实是:在S购物后改去F购物的人并不能省钱，说的是F不省钱。既然F便宜 为什么还不省钱呢。要么是钱之外的因素，要么是题干的其他信息。
钱之外的因素是C, 但那个other factors并没有明确跟省钱挂钩，于是排除。
只能说明围绕题干下手。然后看到了那个total。the ShopperKing totals averagedfive percent higher than the FoodBasket Totals.
题目比较的只是两个地方the very same items 的total averaged price，于是找这个切入点，自然就是A了。

话说这题折磨了我好一阵

Nevertheless, this result does not necessarily show that shoppers at ShopperKing would save money overall by shopping at FoodBasket instead

某某某某某

你很强悍！！！！
牛人一枚啊

aomeisoft7

你很强悍！！！！
牛人一枚啊

-- by 会员 某某某某某 (2010/9/24 22:59:16)

我不牛。。我才考500多分
不敢说，说了就没人问我题了

songhanxiao

那就是说假设的前提一定要包含所有情况？其中一种情况的假设也不可以吗？

leanncx

楼主。。以后我的逻辑就靠你了啊。。
我的逻辑真的蛮烂的。。
你传授传授经验呗~

aomeisoft7

那就是说假设的前提一定要包含所有情况？其中一种情况的假设也不可以吗？

-- by 会员 songhanxiao (2010/9/24 23:41:10)

是呀，必须假设成立，题目的结论才能成立
假设题的办法就是 取非验证
取非，如果削弱结论，则必为假设

aomeisoft7

楼主。。以后我的逻辑就靠你了啊。。
我的逻辑真的蛮烂的。。
你传授传授经验呗~

-- by 会员 leanncx (2010/9/24 23:56:23)

你遇到不会的题目就贴上来一起讨论咯
空说理论的话米有很大用啦