Mathematics
Sets and their representations
The Empty Set, Finite and Infinite Sets, Equal Sets
Practice questions
If A = {x : x is a positive divisor of 60 and x is also a divisor of 15}, what is A?If A ⊆ B, then A ∪ B is equal to what?If A = {x : x ∈ N, 2x + 1 < 10}, where N = {1, 2, 3, ...}, then A is equal to:If \(A=\{1,2,3,4\}\), how many subsets contain 1 or 2?If \(A=\{1,2,3,4,5\}\), how many subsets contain 1 and do not contain 2?If A = {x : x is a letter of the English word “LEVEL”}, what are the elements of A?If A is the set of positive divisors of 18 that are less than 10 and B = {1, 2, 3, 6, 9}, which statement is true?If A = {x ∈ Z : |x − 2| < 2} and B = {1, 2, 3}, which statement is correct?If A = {x : x ∈ Z, −2 ≤ x < 2}, which of the following sets is equal to A?If A = {1, 2, 3, 4}, how many subsets either contain both 2 and 3 or contain neither of them?Which statement about a universal set is correct?If n(U) = 110, n(A) = 58, n(B) = 49 and n(A − B) = 21, then what is n((A ∪ B)′)?If \(A=\{1,2,3\}\) and \(B=\{3,2,1\}\), what is \(A\cup B\)?If n(A) = 35, n(B) = 27, and n(A ∪ B) = 50, what is n(A − B)?If \(A=\{1,2,4,8\}\) and \(B=\{2,4,8,16\}\), how many ordered pairs \((x,y)\) in \(A\times B\) satisfy \(y=2x\)?If \(A=\{1,2,3,4\}\) and \(B=\{1,2,3,4\}\), how many ordered pairs \((x,y)\) in \(A\times B\) satisfy \(x+y\leq 5\)?If \(A=\{0,2,4\}\) and \(B=\{1,3,5\}\), how many ordered pairs in \(A\times B\) have the second coordinate exactly 1 greater than the first coordinate?