first I took 120 and divided by four to show how many cupcakes he can make in thirty minutes (.5 of an hour). this was 30. the reason we divided by four is because in two hours theres four halves.
120÷4=30 for half an hour
30x2=60 this is how many cupcakes he can make in one hour
since we already know how many he makes in two hours we're going to use that
120+60=180 (three hours)
120+60=180 (three hours)180+30 (half an hour) =210
