Question

Each batch of 48 cookies that Amy makes takes 20 minutes in the oven. If the oven is on for 3 hours and 55 minutes (15 minutes for preheating) how many cookies did Amy make?​

Answer 1

3 hours and 55 minutes - 15 minutes would leave 3 hours and 40 minutes. You figure there’s 20 minutes 3 times in an hour so 3x3 is 9 + the extra 2 20 minute periods from the 40 minutes. So 11 batches of cookies, 48x11= 528. Amy made 528 cookies.