Meena bakes 5 dozen cookies for the school’s bake sale. She sells 2 dozen cookies to her biology teacher, Mr. Stone. Her friend Brock buys 7 cookies, and her friend Katy buys twice as many as Brock. How many cookies does Meena have left? Think carefully first, then make a decision:
Meena bakes a total of 5 x 12 = 60 cookies. Mr. Stone buys 2 x 12 = 24 cookies. Brock buys 7 cookies, so Katy buys 2 x 7 = 14 cookies. Meena sells a total of 24 + 7 + 14 = 45 cookies. She has 60 - 45 = 15 cookies left. So, the answer is 15.