Answer: Python Puzzler #521

The answer is D. The program prints:

42

Why?

range(0, 13, 2) starts at 0, goes up in steps of 2, and stops before 13. So the loop adds 0 + 2 + 4 + 6 + 8 + 10 + 12. The total is 42.

Trace table

A trace table follows the program step by step. Here’s this one:

number	total after the loop body
0	0
2	2
4	6
6	12
8	20
10	30
12	42

The code again

total = 0
for number in range(0, 13, 2):
    total = total + number
print(total)