The answer is the option a. Count the days it takes the cats to finish a 3.5 - pound bag of cat food, divide 3.5 by that number of days; multiply the result by 365. When you divide 3.5 pounds by the number of days, you get the average number of pounds that the cats eat per day. Then, when you multiply the average number of pounds that the cats eat per day times 365, you get the number of pounds that the cats eat in 365 days, which is the same that saying in a year.