Jerome burns 4 calmin walking and 10 calmin running He walks

Jerome burns 4 cal/min walking and 10 cal/min running. He walks between 10 and 20 min each day and runs between 30 and 45 min each day. he never spends more than an hour running and walking together. how much time should he spend on each activity to maximize the number of calories he burns?

Wouldn\'t this just be max minutes running (45) and the rest walking (15)?
45(10) + 15(4) = 510 cal max for an hours exercise