Question

|AuB|+|AnB|=18, |A|=13 but |B| = ?​

Answer 1

Answer:

|B|=5

Step-by-step explanation:

|A union B|=|A|+|B| - |A intersection B|

therefore

|A union B|+|A intersection B|=|A|+|B|

therefore

|A|+|B|=18

13 + |B|=18

|B|=5