Answer: Python Puzzler #3787

The answer is A. The program prints:

50

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
46	yes	46
7	no	46
50	yes	50
12	no	50
3	no	50

The code again

numbers = [46, 7, 50, 12, 3]
biggest = 0
for n in numbers:
    if n > biggest:
        biggest = n
print(biggest)