Chapter 10 - Section 10.1 - Counting - 10.1 Assess Your Understanding - Page 687: 12

25

Work Step by Step

By using the counting formula for finite sets: $n(A\cup B)= n(A) + n(B) - n(A\cap B)$ By substituting: $45 = 30 + 40 - n(A\cap B)$ $n(A\cap B)=25$

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.