Answer: Python Puzzler #3648

The answer is B. The program prints:

49

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
23	yes	23
32	yes	32
49	yes	49
38	no	49
25	no	49

The code again

numbers = [23, 32, 49, 38, 25]
biggest = 0
for n in numbers:
    if n > biggest:
        biggest = n
print(biggest)