Question

Need help finding the value for A

Answer 1

`\text{n}(A \bigcup B)` = 6.

Explanation:

We are given that n(A) = 4, n(B) = 5, and
`\text{n}(A \bigcap B)` = 3.

And we have to find the value of
`\text{n}(A \bigcup B)`.

As we know that the union formula is given by;

`\text{n}(A \bigcup B) = \text{n}(A) + \text{n}(B) - \text{n}(A \bigcap B)`

Now, substituting the values given in the question in the above formula, we get;

`\text{n}(A \bigcup B) = 4+5-3`

`\text{n}(A \bigcup B) = 9-3`

`\text{n}(A \bigcup B) = 6`

Hence, the value of
`\text{n}(A \bigcup B)` = 6.