The students have 20 minutes to start.
They get 20 minutes added for the As because 10 times 2 equals <<10*2=20>>20
They get 12 minutes added for the Bs because 12 times 1 equals <<12*1=12>>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*1=5>>5.
In total, they get 47 minutes of recess because 20 plus 20 plus 12 minus 5 equals <<20+20+12-5=47>>47.
#### 47