The teacher decided to rewards his students with extra recess on report card day if they got good grades. Students normally get 20 minutes for recess. He told the students that every A got them 2 extra minutes of recess. Every B got them one extra minute. Every C got them zero extra minutes, but every D got them 1 less minute. When report cards came out there were 10 As, 12 Bs, 14Cs, and 5Ds. In total, how much recess would the students get that day? Let's answer step by step:
The students have 20 minutes to start. They get 20 minutes added for the As because 10 times 2 equals 20. They get 12 minutes added for the Bs because 12 times 1 equals 12. They get no minutes added or subtracted for the Cs because 14 times 0 equals 0. They get 5 minutes taken away for the Ds because 5 times 1 equals 5. In total, they get 47 minutes of recess because 20 plus 20 plus 12 minus 5 equals 47. The answer: 47.