LSAT 80, Logic Game 4, Question 20, LSATHacks

LG Game 4 Question 20 Explanation, by LSATHacks

To understand this explanation, you need to read the setup section. So do that if you haven’t yet. Here’s the setup diagram again:

In the setup, we saw that each group must have an ending value of six. Class 1 buildings are worth four, class 2 are worth two, and class 3 buildings are worth one. 

So, just look for the answer that doesn’t add to six. That’s A, which is CORRECT. It adds to eight.

All the other answers add to six, so it’s possible to get to them after enough trades.