The answer to the puzzle is 1.
Instead of looking at the relationships between adjacent blocks, calculate the total sum of the numbers in each horizontal row. A clear sequence emerges:
Row 1 (Top): 5
Row 2: 7 + 3 = 10
Row 3: 5 + 8 + 2 = 15
The row sums increase by 5 each time (5, 10, 15…). Following this established pattern, the bottom row must add up to 20.
