PSAT Math Multiple-Choice Question 178: Answer and Explanation

Question: 178

If , which of the following is not a possible value of d ?

• A. -2
• B.
• C. 0
• D.

Correct Answer: A

Explanation:

A

Difficulty: Medium

Category: Heart of Algebra/Inequalities

Getting to the Answer: You don't need to separate this compound inequality into pieces. Just remember, whatever you do to one piece, you must do to all three pieces. The fractions in this question make it look more complicated than it really is, so start by clearing them. To do this, multiply everything by the least common denominator, 10:

Now, read the inequality symbols carefully. The value of d is between -2 and not including -2 because of the < symbol, so (A) is the correct answer. Don't let (C) fool you—you can't have a 0 denominator in a rational expression, but in this expression, the variable is in the numerator, so it can equal 0.