2023 AMC 8 Problems/Problem 23
Probability is total favorable outcomes over total outcomes, so we can find these separately to determine the answer.
There are ways to choose the big diamond location from our square grid. From our given problem there are different arrangements of triangles for every square. This implies that from having diamond we are going to have distinct patterns outside of the diamond. This gives a total of favorable cases.
There are 9 squares and 4 possible designs for each square, giving total outcomes. Thus, our desired probability is .
-apex304, SohumUttamchandani, wuwang2002, TaeKim. Cxrupptedpat