PCEP Control Flow, Loops, Lists and Logic Practice Question

A junior developer writes a Python script to sum all numbers greater than 10 from a list. The code is:

numbers = [5, 12, 8, 15, 3] total = 0

for num in numbers:
    if num > 10:

total = total + 1

print(total)

The output is 2, but the expected sum is 27 (12+15). Which change will produce the correct output?

⚠ Common exam trap

Many candidates confuse counting with summing — they see `total = total + 1` and think it's accumulating values, but it actually increments by a constant, not by the variable `num`.

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

✓

Change `total = total + 1` to `total += num`

The original code increments `total` by 1 for each qualifying number, counting them instead of summing their values. Changing `total = total + 1` to `total += num` adds the actual number to the accumulator, producing the correct sum of 12 + 15 = 27.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✗
Change `total = 0` to `total = []`
Why it's wrong here
Initialising total as an empty list makes total + 1 a TypeError, since list and int cannot be concatenated; a list suits collecting matching values, not accumulating a running numeric sum, which requires total = total + num.
✓
Change `total = total + 1` to `total += num`
Why this is correct
Replacing the increment with `total += num` accumulates each qualifying value rather than counting matches, satisfying the stem's requirement to sum numbers greater than 10. The `if num > 10` filter already isolates 12 and 15, so the accumulator yields 27 instead of the tally 2.
✗
Change `if num > 10:` to `if num >= 10:`
Why it's wrong here
This would include 10 if present, but the sum would still be 27 if 10 were not there; however, the problem is that the code counts instead of sums.
✗
Change `for num in numbers:` to `for num in range(numbers):`
Why it's wrong here
Iterating with `range(numbers)` raises a TypeError, since `range()` requires an integer argument, not a list. It is tempting because `range()` genuinely suits index-based loops, such as `for i in range(len(numbers))`, where you then access `numbers[i]` — the correct pattern when you need each element's position as well as its value.

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PCEP Control Flow, Loops, Lists and Logic Practice Question

Why each option matters

Option-by-option breakdown

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