The answer is D. The program prints:
[9, 12, 15]
Why?
append adds one item to the end of the list each time round the loop. The loop runs for n = 3, 4, 5.
Trace table
A trace table follows the program step by step. Here’s this one:
| n | n * 3 | results so far |
|---|---|---|
| 3 | 9 | [9] |
| 4 | 12 | [9, 12] |
| 5 | 15 | [9, 12, 15] |
The code again
results = []
for n in range(3, 6):
results.append(n * 3)
print(results)Try it: change one number in the program and predict the new output before you run it.