This series is designed to help you step up your Data Sufficiency practice while we all spend a little extra time at home during the coronavirus situation; I’m going to publish one practice Data Sufficiency question each day! You can choose to do all of them, or none of them.
Click on the tag “Social Distancing DS Challenge” at the bottom of this post to see all of the questions in this series!
And remember to take whatever precautions you need to stay healthy over the next few weeks!
What is the value of |x| ?
(1) x = |x|
(2) x2 = 9
First, remember that you should always evaluate the statements independently of one another, making sure not to let ideas about one leak over into your analysis of the other.
Statement (1) is insufficient, since there are no clues to the actual value of x. This means that neither choice A (1 is sufficient) nor choice D (each is sufficient) can be correct. Cross them out.
From statement (2)– and without even calculating– we can devise two values for x (one positive, one negative, as we can with any squared number. Here we know that: x2 = 9, so if we had to calculate an actual value, x = +/- 3. And the question is asking us what the absolute value of x would be, so the positive and negative signs are irrelevant. We know from combining statement (2) with the given information in the stem that |x| will equal 3. The correct answer is B.