Question

Use the information given in the figure.

How many are in A or B?

Short answer

$n\left(A\cup B\right)=37$.

Step-by-step solution

Step 1. Given Information.

The given figure is

Step 2. Calculation of a value.

$n\left(A\right)=25,n\left(B\right)=20,n\left(A\cap B\right)=8$

Then, using values in the principle.

Using Counting principle, we get

$\begin{array}{rcl}n\left(A\cup B\right)& =& n\left(A\right)+n\left(B\right)-n\left(A\cap B\right)\\ n\left(A\cup B\right)& =& 25+20-8\\ n\left(A\cup B\right)& =& 37\end{array}$