Boolean Logic Practice

These questions follow Boolean Logic. Every one of them can be settled by typing it into Python — but predict first, because the whole point is to make your prediction match the machine.

Working it out

1. Give the value of each: True and False, True or False, not True, (5 > 3) and (2 > 4).
2. With on_roster = True and form_returned = False, what does each of these produce?

   on_roster and form_returned
   on_roster or form_returned
   not (on_roster and form_returned)

3. Complete the row: if A is False and B is True, then A and B is ___, A or B is ___, and not A is ___.
4. Are not (A and B) and (not A) or (not B) the same for all four combinations of A and B? Show your reasoning.

Using it

5. Find the fault. It is Monday, and this prints Weekend!

   day = "Mon"
   if day == "Sat" or "Sun":
       print("Weekend!")

6. Why does this print False rather than crashing, when sessions is 0?

   print(sessions > 0 and minutes / sessions > 30)

7. Write one condition for: the book is overdue and it has not been renewed. Then give the two variables names that make the line read like the sentence.
8. Challenge. A student can go on the trip if they are 18 or older, or if a guardian has given permission. Write the condition, then explain why or is right here and and would be cruel.

Answers

Answer 1

False, True, False, False. The last one needs both sides to be True; 2 > 4 is False, so the whole expression is False regardless of the first part.

Answer 2

False, True, True in that order. The second line is True because or needs only one side. The third is True because the thing inside the brackets is False, and not flips it — “it is not the case that both are true”.

Answer 3

A and B is False, A or B is True, not A is True. That is row three of the table in Boolean Logic, and it is the row that catches people: an or written where and was meant lets this case through.

Answer 4

Yes — identical in all four combinations. Try it:

print(not (True and False))
print((not True) or (not False))

Both print True. In words, “not both” and “at least one is missing” say the same thing. Write whichever version a person can say out loud.

Answer 5

Python reads it as (day == "Sat") or ("Sun"). A non-empty string counts as True on its own, so the second half is always True, so the whole condition is always True. Every comparison needs both sides:

if day == "Sat" or day == "Sun":

Check it with print(bool("Sun")), which prints True.

Answer 6

and stops as soon as it meets a False. sessions > 0 is False, so Python already knows the whole expression is False and never evaluates the division — which is the only reason there is no ZeroDivisionError. Swapping the two halves around would crash, so the order of an and can matter.

Answer 7

if is_overdue and not renewed_recently:
    print("Send the reminder.")

With is_overdue = True and renewed_recently = False, that prints Send the reminder. Both variables get their values earlier — is_overdue = days_late > 0 — and naming them is the whole point: the librarian can read that condition aloud and tell you whether your rule matches her rule.

Answer 8

if age >= 18 or has_permission:
    print("Cleared for the trip.")

With age = 16 and has_permission = True this is True. and would require both — an 18-year-old would still need a guardian’s note, and a 16-year-old with permission would be refused. The operator is not a technicality here; it is the policy.