Answer: Python Puzzler #3677

The answer is B. The program prints:

58

This answer was checked by running the program for real.

Why?

The loop remembers the biggest number it has seen so far, and replaces it whenever it finds a bigger one. This is how computers find the maximum.

Trace table

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

n	n > biggest?	biggest
47	yes	47
2	no	47
58	yes	58
49	no	58
17	no	58

The code again

numbers = [47, 2, 58, 49, 17]
biggest = 0
for n in numbers:
    if n > biggest:
        biggest = n
print(biggest)