Critical Reasoning

Investigators concluded that human failure was not responsible for the fatal airplane crash last August, and since that time new and more stringent rules for identifying and reporting mechanical problems have been in effect. That accounts for the fact that reports of airplane mechanical problems have increased in frequency by 50 percent since last August.

Which one of the following is an assumption underlying the argument in the passage?

(A) Airplane travel is still relatively safe, despite the increase in reported mechanical problems.

(B) Mechanical problems in airplanes have increased dramatically since last August.

(C) Mechanical problems in airplanes have not increased by 50 percent since last August.

(D) Airlines are less reluctant to report mechanical problems than they previously were.

(E) Mechanical problems in airplanes have become easier to detect since last August.


Please help with this one. Could someone estimate which level of difficulty this question falls under ?

IMO D is the answer. A and E are out of scope.The argument is that strigent rules led to increase in more problems being reported.The missing link here is that airlines are now made to report the problems due to stricter rules.B and C talk about mech problems but not about reports. Whats the OA ?

Focus_gmat:

I will post the OA as soon as I get 3 more opinions about the answer. Why E is out of scope ? Although E does not sound like a good answer for me, it is the best I could choose. E sounds more of an inference than an assumption.

IMO C.
Assumption is that- the application of stringent rules caused the increased reports.
In assumption always keep in mind there are 2 kinds:plain assumption used in the stimuli could be stated
or defender assumption- here the assumption maintains the status quo of the stimuli.

A is out of scope.
B is a weakener. mechanical problems increased so reports increased. (so this has nothing to do with the rules applied)
C- defender assumption. ur maintaining the status quo of the stimuli by eliminating any other possible reasons for the increase in reports. Here when u say Mechanical problems have not increased, we are infact eliminating any other cause that might have caused the increase in reports. So we maintain that the reports are caused only due to stringent rules and nothing else. Perfect answer.
D-If airlines are less reluctant to report now, what does that have to do with rules? The airlines could be less reluctant now for lot of other reasons too.we have to make a second assumption that because of the rules, the airlines are less reluctant.
E- if mechanical problems have been easier to detect, it explains the increase in reports. It infact weakens the statement that because of stringent rules being applied, the number of reports have increased.

fibbonnaci,

Thank you very much. I understand the technique used to construct choice C, but very hard for me to pick it up.

OA C

yup, but u will boil down to C /D. then dissect each option closely. u will see that C makes better sense than D.

Hesham, you could have just viewed this as another explain the phenomenon argument. The word "accounts" in the stimulus gives this away. The phenomenon: reports of problems have increased. The explanation: more stringent rules for identifying and reporting mechanical problems. The assumption: no other explanations. Choice C: if you deny it, the argument clearly falls apart. If we deny Choice C we have: mechanical problems have increased. If mechanical problems have increased then it suggests that the increase in reporting of mechanical problems is due to the fact there ARE more mechanical problems (rather than being due to the fact that reporting procedures are now more stringent.) Thus, the author's argument depends on choice C.

Choice D uses the word "reluctance". Here's a tip: choices that talk about people's motivations, biases, preferences, etc are almost always wrong (unless the argument is specifically about someone's motivations, biases, preferences, etc.)

I agree with you guys. I also think that the right answer is D