Question

How many unique patterns are there in the image?

Hint:

To avoid confusion, scan the image row-by-row and cross out or mark duplicates systematically as you find them.

Answer 1

Correct Answer: 15

Step 1: Group by design.
Scan every tile and cluster ones that are identical (allowing for rotation), setting duplicates aside.
Step 2: Count the clusters.
The number of distinct clusters is the number of unique patterns.
\[ \boxed{\text{Number of distinct pattern groups}} \]