this looks like an LSAT question, and not like a GMAT question. is this an LSAT question?
in general, you shouldn't study with LSAT questions - those questions depend much more on "formal logic" and "rigorous" thinking, and much less on the sort of "common sense" connections that typically characterize GMAT CR problems.

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in any case, there's not much sense in negating the options here, because simply arranging the statements in logical order will reveal the missing link in the reasoning. I.e., in logical order from start to finish, the statements in this argument are:
Programs with unfamiliar commands are expensive to teach.
If a program is expensive to teach, prime purchasers won't use it.
Therefore, programs with unfamiliar commands can't be successful.

here, the argument simply assumes an equivalence / necessary connection between the two boldfaced parts. the rest of the argument is pretty much airtight. so, there's your assumption.

ggmat007 wrote:There are enough gmat questions out there but just to ensure that my cr improves by a considerable extent I took on the challenge of solving LSAT questions.

bad idea. those questions are much more formal/rigorous and use far less intuitive/real-world reasoning than the GMAT questions. if you study those materials too much, the likely effect on your score will be negative.

Do you really recommend not to solve LSAT questions and concentrate on d ones which are specific to GMAT types?

in other words, "Ron, do you really mean what you wrote in that post up there?"

Yes.

I don't understand "D ones". what does D stand for?

ggmat007 wrote:Also is it advisable to solve RC questions from LSAT Set

honestly, you shouldn't even need to do all the RC's in the GMAT official guides; those books alone contain way, way, way more RC's than you should ever have to use. so, the thought of using non-GMAC sources shouldn't even enter the picture, since there's already a huge excess of RC material from GMAC.

remember that there's zero knowledge to acquire in RC; it's just a matter of understanding how the questions work, and adopting the right mentality toward them. furthermore, there are only 2 such mentalities - one for big-picture questions, and one for detail-based questions.

so, by the time you get through, say, 1/2 of the RC's in the official guide, you either (a) have the right mentality toward the questions, or (b) don't have it.
at that point, you aren't going to accomplish much by studying more RC's. if it's (a), then you are already good to go; if it's (b), then doing more RC's might start to work against you, by solidifying bad habits.

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the other possible situation, of course, would be a student who doesn't read english well enough to do the RC's.
in that case, doing tons and tons of RC's would also be a waste of time - and a waste of those RC's!
if anyone reading this post is in that situation (i.e., in need of general improvement in reading english in general), then the best way to go about that is to just read tons and tons of stuff in english. then, once you've improved your reading skills (give it at least a year), come back to the GMAT RC's and have at them again.

hemant_rajput wrote:He means "the one"; messaging language- d stands for the

thanks. i suppose i am not up on the latest netspeak.

on a forum like this one - whose entire point is to teach and promote the reading and writing of formal written english (!!) - that sort of thing strikes me as a bit inapposite/unprofessional, especially in questions aimed at a moderator. (it wouldn't seem so weird in random chat between members.)
not a big deal, but ... interesting.

ggmat007 wrote:Ron first and foremost I am really glad to receive a response from you. Thanks a lot for that. I was little confused with LSAT stuff but now I am going to solely concentrate on GMAT RC and GMAT CR.

good.
you shouldn't run out of those. in fact, you should be done preparing for those two tasks (especially RC) long before you exhaust those questions.

Kindly excuse me for the type of language I used in posting my query. I always avoid such habit when I write official emails. Will ensure to carry on the same here as well.

i'm not offended by it; i just think it's weird, in this kind of environment (a professional/expert advice board), that's all.