Last Updated on May 9, 2023
GMAT OFFICIAL GUIDE DS –
Solution:
Let’s begin by sketching the number line.
We need to determine whether r is closest to zero.
Statement One Alone:
q = -s
Since q = -s, q and s are opposites. For example, q = 2 and s = -2, or, q = -3 and s = 3. However, since q is to the left of s, q must be negative and s must be positive. Because q and s are opposites, zero must be exactly halfway between q and s. Since variable r is also between q and s we know that r is closer to zero than any other variable on our number line.
Statement one is sufficient to answer the question. We can eliminate answer choices B, C, and D.
Statement Two Alone:
-t < q
Since statement two is comparing the possible values of –t and q with an inequality, we do not have any significant information that will allow us to determine an exact location of zero on the number line. For example, if q = 1, r = 2, s = 3 and t = 4, then q is closer to 0 than r is. If q = -1, r = 0, s = 1, and t = 2, then r is closest to 0 since r itself is 0. Since we can have two contradictory scenarios, statement two does not provide enough information to answer the question.
Answer: A
