Question

Given n(A) = 1300, n(A U B) = 2290, and n(A n B) = 360, find n(B).

Answer 1

n(B) = 1350

Explanation:

Using Venn sets, we have that:

`n(A \cup B) = n(A) + n(B) - n(A \cap B)`

Three values are given in the exercise.

The other is n(B), which we have to find. So

`n(A \cup B) = n(A) + n(B) - n(A \cap B)`

`2290 = 1300 + n(B) - 360`

`940 + n(B) = 2290`

`n(B) = 2290 - 940 = 1350`

So

n(B) = 1350