Answer: What Comes Next? #343

The answer is B: 41.

The finished pattern: 2, 7, 15, 20, 28, 33, 41.
The finished pattern.

The rule

Add 5, then add 8, then 5, then 8, and so on. The pattern of adding takes turns.

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.

adds = [5, 8]
number = 2
for step in range(7):
    print(number)
    number = number + adds[step % 2]

When you run it, Python prints:

2
7
15
20
28
33
41

Pixel says: Try changing a number in the code and run it again. Can you make the pattern go on for 20 steps? Meow!