From the whole numbers 1 to 19, A is the even numbers and B is the numbers above 13. What is the probability of A or B?

1. The sample space holds 19 numbers, from 1 up to 19. 2. Event A holds the nine even numbers 2, 4, 6, 8, 10, 12, 14, 16 and 18. 3. Event B holds the six numbers 14, 15, 16, 17, 18 and 19. 4. Their intersection is 14, 16 and 18, which is three numbers. 5. The union is 9 plus 6 minus 3, which is 12 numbers, giving a probability of 12/19. 6. Adding 9 and 6 without subtracting the overlap gives 15/19 and counts the three shared numbers twice. _Source: OpenStax Introductory Business Statistics (CC BY 4.0), Ch 3 "Probability Topics", section 3.1 Terminology_