Here are some possible MCQs 

 Each question has four options, and the correct answer is marked with an asterisk.

What is the cardinality of a set? a) The number of elements in the set b) The number of subsets of the set c) The measure of how many elements the set contains* d) The measure of how many subsets the set contains

What does it mean for a mapping to be injective? a) It maps different elements to different elements* b) It maps different elements to the same element c) It maps every element in the domain to an element in the codomain d) It maps every element in the codomain to an element in the domain

Which of these sets is an example of a countable set? a) The set of all real numbers b) The set of all rational numbers* c) The set of all functions from ℕ to ℝ d) The set of all subsets of ℝ

Which of these sets has cardinality ℵ₀? a) The set of all natural numbers* b) The set of all integers c) The set of all even natural numbers d) All of the above

Which of these mappings is not injective? a) f(n) = n + 1 b) f(n) = n² + 1 c) f(n) = floor(n/2)* d) f(n) = 2n

What is the inverse image of a function f? a) The function that maps every output of f to its corresponding input* b) The function that maps every input of f to its corresponding output c) The function that maps every output of f to a different output d) The function that maps every input of f to a different input

What is the domain and range of the function f(n) = floor(n/2)? a) Domain: ℕ, Range: ℕ* b) Domain: ℕ, Range: ℤ c) Domain: ℤ, Range: ℕ d) Domain: ℤ, Range: ℤ

What is the cardinality of the set S = {f(n) | n ∈ ℕ}, where f(n) = floor(n/2)? a) ℵ₀* b) ℵ₁ c) 2ℵ₀ d) 2|ℝ|

What is another name for cardinality ℵ₀? a) Aleph-null* b) Aleph-one c) Beth-null d) Beth-one

What is the continuum hypothesis? a) The hypothesis that there are no sets with cardinality between ℕ and ℝ* b) The hypothesis that there are no sets with cardinality between ℝ and ℝℕ c) The hypothesis that there are no sets with cardinality greater than ℝℕ d) The hypothesis that there are no sets with cardinality less than ℕ

What is the cardinality of the set of all irrational numbers? a) ℵ₀ b) ℵ₁ c) 2ℵ₀* d) 2|ℝ|

What does it mean for a mapping to be bijective? a) It maps different elements to different elements and every element in the codomain to an element in the domain* b) It maps different elements to different elements and every element in the domain to an element in the codomain c) It maps different elements to the same element and every element in the codomain to an element in the domain d) It maps different elements to the same element and every element in the domain to an element in the codomain

Which of these sets is an example of a finite set? a) The set of all prime numbers b) The set of all even natural numbers c) The set of all natural numbers less than 10* d) The set of all natural numbers divisible by 10

Which of these sets has cardinality 5? a) The set of all Platonic solids* b) The set of all regular polygons c) The set of all polygons with five sides d) The set of all polygons with five vertices

Which of these mappings is bijective? a) f(n) = n + 1* b) f(n) = n² + 1 c) f(n) = floor(n/2) d) f(n) = 2n