We have 10 numbers. If a customer gets an even number, they will get a 15 percent discount. We know that there are 5 odd and 5 even numbers, therefore there is a 5/10 (50 percent) probability a customer gets a 15 percent discount. We need to find out how many odd numbers are greater than 6. 7 and 9. There are two odd numbers greater than 6, so there is a 2/10 (20 percent) probability a customer gets a 30 percent discount. We also need to find the probability if a customer doesn’t meet any of that criteria. If we add 5/10 + 2/10, we will get 7/10. 10/10 - 7/10 = 3/10 (30 percent).