Answer:
(a) false
(b) true
(c) true
(d) true
(e) false
(f) true
(g) false
(h) true
(i) true
Step-by-step explanation:
(a) 15 ⊂ A, since 15 is not a set, but an element, we cannot say of an element to be subset of a set. False
(b) {15} ⊂ A The subset {15} is a subset of A, since every element of {15}, that is 15, belongs to A.
15 ∈ {15} and 15 ∈ { x ∈ Z: x is an integer multiple of 3 } 15 is an integer multiple of 3. since 15/3=5. True
(c)∅ ⊂ A
∅ is a subset of any set. True
(d) A ⊆ A
A is a subset of itself. True
(e)∅ ∈ B
∅ is not an element, it is a subset, so it does not belong to any set. False
(f)A is an infinite set.
Yes, there are infinite integers multiple of 3. True
(g)B is a finite set.
No, there are infinite integers that are perfect squares. False
(h)|E| = 3
The number of elements that belong to E are 3. True
(i)|E| = |F|
The number of elements that belong to F are 3. So is the number of elements of E. True
