GRE Quantitative Practice, Quantitative Comparison
Question 4
l_{1}  l_{2}  
Quantity A w + y  Quantity B w + z 

Explanatory Answer
You can cancel the term w from both quantities, leaving the comparison between y and z. Since the two lines are parallel, corresponding angles formed by the transversal are congruent (equal in degree measure, or size). Accordingly, y = z, and the two quantities are equal. The correct response is (C).