Handling “Analyze the Answer Choices” Questions
Consider the following two questions:
Question #1:
If 10 is the greatest common divisor of positive integers [pmath]x[/pmath]and[pmath]y[/pmath], and 20 is the lowest common multiple of [pmath]x[/pmath] and [pmath]y[/pmath], what is the value of [pmath]xy[/pmath]?
A) 15B) 20
C) 30
D) 100
E) 200
Question #2:
Which of the following CANNOT be the greatest common divisor of positive integers [pmath]x[/pmath]and[pmath]y[/pmath]?A) 1
B) [pmath]2x - y[/pmath]
C)[pmath]y[/pmath]
D)[pmath]x[/pmath]
E) [pmath]x + 2y[/pmath]
Notice that we dont need the answer choices to solve question #1, but we need them to solve question #2. Question #2 falls into a category of questions well call Analyze the Answer Choices questions, because they require us to analyze each answer choice. Questions of this nature typically ask Which of the following COULD be ? or Which of the following CANNOT be ? but there are other variations as well.
The ONLY advice I'm offering in this brief article
When you encounter an Analyze the Answer Choices question, always check the answer choices from E to A, because the correct answer is typically closer to the bottom than to the top.
Why is this?
Presumably, the test-makers know that most people check answer choices from A to E, so placing the correct answer near the bottom ensures that test-takers spend more time locating for the correct answer.
Now, I should mention that Ive offered this advice for many years, but Ive never actually backed it up with hard evidence beyond casual observations of questions in this category. For this article, I decided to find that hard evidence. So, I checked all of the Problem Solving questions in three Official Guides for GMAT Review (the 8th edition, 11th edition and 13th edition). Within those three resources, I found 28 different Analyze the Answer Choices questions. The frequencies were as follows:
A: 2 correct answersB: 2 correct answers
C: 6 correct answers
D: 6 correct answers
E: 12 correct answers
As you can see, youll likely find the correct answer faster by checking the answer choices from E to A.
Aside: Incidentally, E is the correct answer for question #1, and E is the correct answer for question #2. If youd like help with either question, please post your query on the BTG forum.