Common core test practice. a book of coupons contains 18 restaurant coupons, 12 hotel coupons, and 9 movie theater coupons. what fraction of the coupons are restaurant coupons?

So first you add all of the coupons together to get 39 total coupons. This means that 18/39 coupons are restaurant coupons. You can reduce the fraction by dividing both the numerator and denominator by 3 to get 6/13

18 plus 12 plus 9 is 39 so 39 coupons so 18/39 turned into a decimal is 46%