Good, Better, Best: Overcoming Tricky Weak Answers in GMAT Critical Reasoning

When going through answer choices, and this is especially true in Critical Reasoning, be careful not to dismiss weak or convoluted answers. If you cannot find a “fatal flaw” with an answer choice, make a small mark next to that letter on your scratch pad but do not eliminate the choice completely. Continue reading the other choices to see if you can eliminate them completely. After you’ve read through all the options, consider your best available choices. You will sometimes find that the weak choice is actually the last remaining option and therefore must be correct.

Here’s an example of a weak answer choice being correct. Cunningly, GMAC makes this choice (A), hoping you will eliminate it and look for the correct answer in the remaining options.

CR Question (from: GMATClub)

Which of the following most logically completes the argument?

Researchers recently asked dozens of shoppers, chosen at random coming out of a FoodBasket supermarket, what they had purchased. The prices of the very same items at the nearest ShopperKing supermarket were totaled and compared with the FoodBasket total. The ShopperKing totals averaged five percent higher than the FoodBasket totals. Nevertheless, this result does not necessarily show that shoppers at ShopperKing would save money overall by shopping at FoodBasket instead, since ______.

A. shoppers who shop regularly at a given supermarket generally choose that store for the low prices offered on the items that they purchase most often

B. for shoppers with more than 20 items, the ShopperKing totals averaged more than five percent higher than the FoodBasket totals

C. many shoppers consider factors other than price in choosing the supermarket at which they shop most regularly

D. there is little variation from month to month in the overall quantity of purchases made at supermarkets by a given shopper

E. none of the people who conducted the research were employees of the FoodBasket supermarket

Answer
The best answer is (A). Remember, the best answer is not necessarily a “good” piece of logic, just more correct than the other choices. This question illustrates this.

This is a typical CR “Survey” question, testing your ability to detect strong conclusions based on weak evidence. Whenever you see a question with any number of people surveyed, you should immediately be on the look-out for any very specific conclusions based on this survey. Generally, a survey, no matter how broad or well thought-out, will not be enough to warrant strong conclusions.

Note that answer A does not rely on anyone sampled in the survey and instead states a general truism about shopping habits.

Choice (B) is incorrect not only because we are still dealing with sample sizes, but also because the sub-sample of those surveyed who had over twenty items is unknown — what if it was just one or two people? Clearly not enough to draw a conclusion.

Choices (C) and (E) have nothing to do with the question.

Choice (D) attempts to confuse you by leveraging a piece of evidence offered in choice (B).