Logic

A fun problem type that doesn't appear often. When it does, however, it always manages to trick lots of people. A few key things to note:

1. A contrapositive of a statement is always true, assuming that the conditional statement is true 

1985 AJHSME Problem 25

1987 AJHSME Problem 20

2. Knights and Knaves (or truth tellers and liars) are fun logic puzzles. Here is some tips from brilliant on how to solve these puzzles. 

1986 AJHSME Problem 22

1987 AJHSME Problem 17

3. Cases and Graphs

2025 AMC 8 Problem 21