00:01
In this question, i want to give examples of sets a and b, such that the number of elements in set a is 4.
00:08
That's what this notation means.
00:10
Then the number of elements in set b is 5.
00:15
And then when i combine the two sets, the number of elements in a union b is going to be 9.
00:24
So we'll write out these sets explicitly.
00:28
So what i can do is i can say that set a consists of the integers from 1 through 4.
00:34
So set a consists of the positive integers 1, 2, 3, and 4.
00:41
Then there are indeed 4 elements in set a.
00:45
For set b, i'm going to have set b consists of the integers from 5 through 9.
00:52
So 5, 6, 7, 8, and 9...