Count The Exact Number of Balls.

is 16—not 13, and not 14. Counting from top to bottom, the five rows contain 2, 5, 2, 5, and 2 balls. Add those numbers together, and neither suggested answer survives. The empty spaces interrupt the arrangement, making a quick scan less reliable than it feels. A steadier approach is to move left to right across each row, counting every ball once before continue reading …