If the universal set U is defined by
U = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10} and
A = {1, 2, 3, 4 }
B = {3, 4, 5, 6, 7}
What is n(A ∩ B) ?
what elements are in both A and B?
{3,4}
To find the intersection of two sets A and B, we need to identify the elements that are common to both sets. In this case, A = {1, 2, 3, 4} and B = {3, 4, 5, 6, 7}.
The common elements between A and B are 3 and 4. Therefore, the intersection of A and B, denoted by A ∩ B, is {3, 4}.
To find the number of elements in the intersection set, we calculate its cardinality, denoted by n(A ∩ B).
In this case, the intersection set {3, 4} has 2 elements. Therefore, n(A ∩ B) = 2.