Answer: What Comes Next? #409

The answer is B: 225.

The rule

These are square numbers: 9 × 9, 10 × 10, 11 × 11, and so on. You can make each one as a square of dots!

The pattern as Python code

Here is a tiny Python program that follows the same rule. Type it into IDLE and run it to print the whole pattern, including the answer.

for n in range(9, 16):
    print(n * n)

When you run it, Python prints:

81
100
121
144
169
196
225