2019 Mock AMC 10B Problems/Problem 14
Solution 1
There are five points, and to make a triangle we need 3, so the number of ways is just 
This is option choice (A).
- Armpit Splash 💦
- Edits by Continuous_Pi
Note: This solution is wrong because we must consider when a subset of the points are collinear, creating degenerate triangles.
