APCSP Boolean Logic 3

Question 1

What does the XOR (exclusive OR) operator return?

Accepted Answer

TRUE when exactly one input is TRUE

Answer

XOR returns TRUE only when exactly one of its inputs is TRUE, unlike regular OR which also returns TRUE when both inputs are TRUE.

Question 2

According to De Morgan's first law, NOT(A AND B) is equivalent to:

Accepted Answer

NOT(A) OR NOT(B)

Answer

De Morgan's first law states: NOT(A AND B) = NOT(A) OR NOT(B).

Question 3

Which expression is equivalent to NOT(A OR B) by De Morgan's second law?

Accepted Answer

NOT(A) AND NOT(B)

Answer

De Morgan's second law states: NOT(A OR B) = NOT(A) AND NOT(B).

Question 4

Why are Boolean conditions used in if-statements in programming?

Accepted Answer

To determine which branch of code to execute

Answer

Boolean conditions in if-statements evaluate to TRUE or FALSE to control which code path the program follows.

Question 5

A spam filter marks email as spam if: (has_suspicious_link OR from_unknown_sender) AND NOT(in_whitelist). When is email NOT marked as spam?

Accepted Answer

When the sender is in the whitelist

Answer

If in_whitelist is TRUE, then NOT(in_whitelist) is FALSE, making the entire AND expression FALSE so the email is not marked as spam.

(APCSP) AP Computer Science Principles Practice Test