# MAT2051 Unit 2 Quiz (October 2019)

MAT 2051 Discrete Mathematics

Unit 2 Quiz

Question 1 What is a set?

a. An unordered collection of objects.

b. An ordered collection of objects.

c. The study of reasoning.

d. A partition of numbers.

Question 2 What is the cardinality of the set X = {1, 5, 3, 8, 10}?

a. 5.

b. 1.

c. 10.

d. 27.

Question 3 What value replaces ? in the following truth table?

a. 0.

b. 1.

c. Cannot solve with the given information.

d. Can be either 0 or 1.

Question 4 Let:

Q: Jerry goes to college.

Assume the statement P ? Q is true.

If Jerry does not go to college, did he receive his scholarship?

a. Yes, because the converse of the statement is true.

b. No, because the contrapositive of the statement is true.

c. There is not enough information.

d. Can be either.

Question 5 What is deductive reasoning?

a. A hypothesis together with a conclusion.

b. Valid arguments of a hypothesis.

c. The process of drawing a conclusion from a sequence of propositions.

d. A simplification of the rules of inference.

Question 6 Assume that ~, v, and ^ are the NOT, OR, and AND symbols, respectively. Use a truth table to determine if the following Boolean equation ~x1 v (x2 ^ x1):

a. Is functionally identical to an AND gate.

b. Is functionally identical to an OR gate.

c. Is not like an AND or an OR gate.

d. Is a NOT gate.

Question 7 The function f(x) = x + 3 is best described as:

Onto the reals.

a. One-to-one with the reals.

b. Onto the reals.

c. Is a bijection with the reals.

d. Is neither one-to-one nor onto.

Question 8 Given a hash function h(n) = n mod 5, what would a computerâ€™s memory cells look like if we were to input values 2, 10, and 14?

Unit 2 Quiz, Question 8. The answers are tables, they are noted here in order (matched with the letter.)[D]

a. a.

b. b.

c. c.

d. d.

Question 9 How many strings of length 2 can be created from the set X = {a, b, c} without replacement (without replacement simply means that you cannot use the same element more than once).

a. 6.

b. 8.

c. 24.

d. 12.

e. 16.

Question 10 Represent the following database as n-ary tuples:

Database Table.[D]