Answer: What Comes Next? #403

The answer is C: 3645.

The rule

Multiply by 3 each time.

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.

number = 5
for step in range(7):
    print(number)
    number = number * 3

When you run it, Python prints:

5
15
45
135
405
1215
3645