Logic and Proof Quizzes

Think you’ve got your head wrapped around Logic and Proof? Put your knowledge to the test. Good luck — the Stickman is counting on you!
Q. Is the statement "1 + 1 = 2 or any two points determine a line" true or false?


True
False
Both true and false
Not enough information
All of the above
Q. What is the converse of rz?


rz
zr
not z → not r
r → not r
not r → not z
Q. Which of "and," "not," and "or" link two statements together?


"and"
"or"
"not"
"and" and "or"
"and," "not," and "or"
Q. How many values of x make the statement "x ≤ 5 and x ≥ 5" true?


None
1
2
5
Infinitely many
Q. Suppose we know ab, bc. If we know b is true, may we infer c?


No
Yes, by detachment
Yes, by syllogism
Yes, by transitivity
Yes, by reflexivity
Q. Is the contrapositive of "Everything brown is a dog" true?


No, and a white dog is a counterexample
No, and a brown hat is a counterexample
No, and a white hat is a counterexample
No, and a brown dog is a counterexample
Yes
Q. Which is an example of something "white or not soft?"


Pink cotton ball
Blue bunny rabbit
Gray moldy marshmallow
White rock candy
Green pillow
Q. Suppose that pq and pr. May we infer that qr?


Yes, by detachment
Yes, by symmetry
Yes, by syllogism
Yes, by addition
No
Q. What is the converse of not p → not q?


pq
not q → not p
qp
not pq
p → not q
Q. The statements pq and qr are given. If we know q to be true, which of the following CANNOT be assumed as true?


p
pq
q
qr
r