If t and x are integers, what is the value of x?

Correct answer is (E). 

In all of my classes and tutoring sessions, I emphasize how important it is to “spot the con” and to critically analyze your decision-making process when working through GMAT problems. This frequently missed question is a wonderful example of what happens when you don’t remain critical. In statement (1), you are given a piece of information that the test writers purposefully want you to determine is insufficient. You look at statement (1), glance at statement (2), and immediately realize that x and t could be positive or negative in statement (1) alone, making it insufficient. People feel good about themselves for identifying this fact and quickly pick (C), since adding statement (2) seems to guarantee that x and t are positive 2 and positive 3, respectively. 

Anytime the test writers can create a scenario in which you have a dopamine response and feel good about finding a trap, you are likely to stop being critical. The positive/negative issues present in this question are a shiny penny—so many people pick (C) because they only focus on the positive/negative ambiguity in statement (1), and statement (2) guarantees they are positive. However, when taken together, all that statements (1) and (2) tell you is that the ratio of x:t must be 2:3 and x and t must be positive. This still leaves an infinite number of possibilities for the two values: 2 and 3, 4 and 6, 6 and 9, 8 and 12, etc. Since the value for x cannot be determined, the correct answer is (E).

If both statements together still result in an infinite number of possibilities for the value of x, why do a majority of high-performing students still pick (C), thinking x must be 2? Because they don’t understand the con and they let their guard down! Just because you find one “con” in a question (in this example, the positive/negative issue), does not mean there aren’t others still present! 

All hard questions on this exam work as follows: good test takers find the first “con” in the problem and are satisfied to stop at that point; the best test takers remain highly critical even after that infusion of dopamine from identifying the first “con” and keep looking for traps, eventually proving the correct answer. As in business, success on the GMAT requires hypervigilance—one lazy moment and you get a very doable question wrong!