jmc

Question

At Central Middle School, the 108 students who take the AMC 8 meet in the evening to talk about food and eat an average of two cookies apiece. Hansel and Gretel are baking Bonnie's Best Bar Cookies this year. Their recipe, which makes a pan of 15 cookies, lists these items: 112 cups flour, 2 eggs, 3 tablespoons butter, 34 cups sugar, and 1 package of chocolate drops. They will make full recipes, not partial recipes. Hansel and Gretel must make enough pans of cookies to supply 216 cookies. There are 8 tablespoons in a stick of butter. How many sticks of butter will be needed? (Some butter may be leftover, of course.)

Accepted Answer

For 216 cookies, you need to make 21615 = 14.4 pans. Since fractional pans are forbidden, round up to make 21615 = 15 pans. There are 3 tablespoons of butter per pan, meaning 3 15 = 45 tablespoons of butter are required for 15 pans. Each stick of butter has 8 tablespoons, so we need 458 = 5.625 sticks of butter. However, we must round up again because partial sticks of butter are forbidden! Thus, we need 458 = 6 sticks of butter, and the answer is 6.