Source: Princeton Online Test 2 , Q31

To formulate an all-purpose dietary supplement that could satisfy an average adult’s requirement for vitamins, minerals, and fiber would be both nearly impossible and would fail to sell because consumers can more cheaply combine already available products to meet their specific needs.

be both nearly impossible and would fail to sell because

be both nearly impossible as well as a failure to sell since

both be nearly impossible and a failure to sell since

be nearly impossible as well as a failure to sell because

be nearly impossible and would fail to sell because

we'll apply the all-purpose process of elimination filter here, since you've not posted any particular questions.

both ... and: the phrases following each of these words must be exactly parallel. you must look only at the words actually following 'both' and 'and'; you can't incorporate other nearby words in an effort to make the construction seem correct.
- choice a is eliminated (nearly impossible is not parallel to would fail to sell)
- choice c is eliminated (be nearly impossible is not parallel to a failure to sell)

redundancy: you can't put 'both' and 'as well as' in the same construction
- choice b is eliminated

wording issues: the subject of the sentence is 'to formulate an all-purpose dietary supplement...', so it makes no sense to say that this subject could 'fail to sell'.
- choices a and e are eliminated

choice d still stands, and so it's 'correct'.
i'm using quote marks because i don't like that choice much, either; i think the wording 'a failure to sell' seems to refer to a failed marketing plan, and doesn't seem to correspond closely enough to the subject of this sentence. in fact, imho, all the answer choices are wrong because none of them has a 2nd verb that really matches the subject ... but choice d is the least wrong.

Ron,

I agree with you that none of the five answer choices made much sense. However, I think E might be a better answer than D. Here is my reasoning:

Choice D, be nearly impossible as well as a failure to sell because, sounds as if it is missing a verb between as well as and a failure. I don't know whether constructions before and after "as well as" should be parallel. In this case, it is hard for me to think that be applies to both nearly impossible and a failure to sell - simply does not sound right to my ears.

As for Choice E, I actually interpreted the phrase fail to sell to be "fail to move past certain approval process" (e.g., making a presentation to your boss in order to obtain approval on some idea). Assume that you agree with my interpretation and then take look at the answer choice again, then now the answer choice would contain the WOULD + VERB construction both before and after and, making the comparison parallel.

What are you thoughts on this?

Thanks!

minor thought: you have a point regarding dubious parallelism in choice d, because 'nearly impossible' is an adj. phrase and 'a failure' is a noun.

minor thought #2: 'sell' should be interpreted to mean nothing more than 'sell'. creative interpretations are strongly discouraged on the real gmat, which is very literal about eeeeevvvvverything.

major thought: this problem is junk. since it's from a secondary source (i.e., not official material), let's just ignore it and move on.

i dont like the question either. BUt what is wrong with a?

Take a look at Ron's first post, above. The idiom "both X and Y" requires X and Y to be parallel and they are not in A. In addition, A is saying that "to formulate (a supplement) would fail to sell," not that the supplement itself would fail to sell. "To formulate" is not something that can be sold.