The Princeton Review - Princeton Review PSAT 8_9 Prep-Random House Children's Books (2021)

B)
C)
D)
Here’s How to Crack It
The question asks for the system of equations that represents the
situation. Rather than taking the time to create your own system
based on the information, then looking to match yours to one of the
answer choices, use Bite-Sized Pieces and Process of Elimination.
Just translate one small, straightforward piece, such as the fact that
40 cards were sold. Those cards were either rare, represented by r, or
common, represented by c. Therefore, one equation must be r + c =
40. Eliminate any answers that don’t include this equation, such as
(A) and (C). Now, rather than translating the other equation needed,
take a moment to compare the remaining answers. The difference
between the two is that (B) has (40)(296) as the right side of the first
equation, while (D) only has 296 there. The number 296 appears in
the question as the total amount of money the sports enthusiast
spent, so this value should not be multiplied by 40, the number of
cards purchased (the enthusiast did NOT spend $296 on of each of
the cards). Thus, you can eliminate (B) and know that the correct
answer is (D). Using POE in small pieces this way is very efficient!