LSAT-17-3-2

bigmouse

People who are red/green color-blind cannot distinguish between green and brown, Gerald cannot distinguish between green and brown. Therefore Gerald is red/green color-blind. Which one of the following most closely parallels the reasoning in the argument presented in the passage?

(A) People who are fair-skinned suffer from sunburn. William is fair-skinned. Therefore William suffers from sunburn.

(B) People who are suffering from sinusitis lose their sense of smell. Mary has lost her sense of smell. Therefore Mary is suffering from sinusitis.

(C) People who have suffered from jaundice cannot become blood donors, Jean is a blood donor. Therefore Jean has not suffered from jaundice.

(D) People who are color-blind cannot become airline pilots. Arthur is color-blind. Therefore Arthur cannot become an airline pilot.

(E) People who are diabetic cannot eat large amounts of sugar. Freda is diabetic, Therefore Freda is on a special diet.

答案是B，为什么C不好？难道仅是因为C的时态和原文不一致吗？多谢各位能帮忙解答一下～～

robertchu

Original passage is logically incorrect: A --> B;  since B, then A.  

Answer choice A has the same logic fallacy.

Answer choice C actually is logically correct, therefore is not the right answer.

bigmouse

thanks a lot ! In fact , I find I very stupid~~~

robertchu

not need to self-deprecate.

take it easy and enjoy.

Bensontuo

bigmouse 发表于 2005-1-23 14:12
People who are red/green color-blind cannot distinguish between green and brown, Gerald cannot disti ...

If A ---> B / C ---> B / so, C ---> A

A. if A ---> B / C ---> A / So C ---> B

B. If A ---> B / C ---> B / So C ---> A

C. If A --->~ B / C ---> B / So C ---> ~ A

D. If A ---> ~B / C ---> A / So C ---> ~B

E. If A ---> ~B / C ---> A / So C ---> D

you know which one is the best.