Whatever the question type there two things that are a must-do if you want to develop a flawless technique to answer GMAT® Critical Reasoning Questions:
• Precisely Identify The Argument
• Clearly Define What The Right Option Should Do
The GMAT® Evaluate Question below best illustrates how to apply this technique.
Most of the world’s supply of uranium comes from mines. It is possible to extract uranium from seawater but the cost of doing so is greater than the price that uranium fetches on the world market. Therefore, until the cost of extracting uranium from seawater can somehow be reduced, this method of obtaining uranium is unlikely to be commercially viable.
Which of the following would be most useful to determine in evaluating the argument?
(A) Whether the uranium in deposits on land is being rapidly depleted.
(B) Whether most uranium is used near where it is mined.
(C) Whether there are any technological advances that show the promise of reducing the cost of extracting uranium from seawater
(D) Whether the total amount of uranium in seawater is significantly greater than the total amount of uranium on land.
(E) Whether uranium can be extracted from freshwater at a cost similar to the cost of extracting it from seawater.
The first task is to precisely identify the argument — unless the cost comes down, extraction of uranium from seawater will remain an unviable.
The question is asking you identify the information that will help you evaluate this argument. So what do you need to check — can it become viable even without the cost coming down?
Almost 9 out of 10 students confidently choose option (C) to be correct choice.
The best way to answer such questions is to take each option and evaluate the answers to the question posed. In the above question the answer to each of the options can either be YES or NO.
If the answer to (C) is YES, it means that in future the cost of extracting from sea-water will come down. But this does not help you evaluate the argument in any way.
For example, if someone tells you that you cannot get an admit into XYZ College without scoring a 700 on the GMAT®, how will you evaluate that argument? You will check if there are candidates who got an admit with a score less than 700.
So knowing the answer to the question posed in option (C) is equivalent to checking whether you can get a 700, this is not the same as evaluating whether you need a 700 in the first place!
So knowing whether the cost of extraction will come down is not going to tell you whether it needs to come down.
Let us look at option A. The answer to the question posed in this option can again be a YES or NO.
If the answer is YES, that is, the uranium in land deposits is rapidly decreasing, then there will be no option but to very soon start extracting it from sea irrespective of the cost.
If the answer is NO, then it means that demand for uranium can be met by extracting uranium from land at a cheaper cost, so extraction from seawater will remain infeasible.
So, knowing the answer to the question posed in option A will help us evaluate whether the argument is valid or not.
Hence, to answer Evaluate Questions on the GMAT® correctly, ensure that you precisely identify the argument being made and then clearly define what the right option should do.
In every real-life problem-solving situation the first step starts with asking questions and gathering information. This question type tests whether you can have the ability to ask the right questions.