A lottery ticket contains 5 numbers chosen from the numbers 1 to 40. The winning ticket is the one that matches all the 5 numbers in the correct order. The second prize winner matches four of the five numbers in the correct order. What is the probability of winning the first or second prize?

Answer 1

5 numbers = 1/40 * 1/39 * 1/38 * 1/37 *1/36 = ?

4 numbers = 1/40 * 1/39 * 1/38 * 1/37 = ?

Either-or probabilities are found by adding the individual probabilities.