请教各位大牛McGrawHill中两道逻辑题目

sdcar2010

Car.

C) will not be a weakener if E) is right. In other words, C) makes an assumption that the drivers will drive faster than 100 mph. Such an assumption may or may not be right. Further, even if C) is correct, a driver can drive between 80-100 mph, and arrive at the destination safely and faster. The conclusion still holds.

E) however, makes the conclusion totally wrong. Therefore, E is the better answer.

sdcar2010

可以推断是因为桥的修建方便了交通所以才修的casino

This is your OWN assumption. May not be true.  Never add your own assumption when dealing with GMAT CR questions.  That is a cardinal sin for GMAT testers.

sdcar2010

如果West Countway County 的人要去East Countway ，那么桥只是缩短了去的时间，桥没有之后他们不一定就不去了

Exactly!  Then shutting down the bridge would SOLVE the traffic congestion problem because the decreasing number of outsiders. Thus, this is a strengthener.