John can produce a higher grade in his upcoming exam if he devotes time to reading his class notes and solving practice problems. His grade (G) is...

John can produce a higher grade in his upcoming exam if he devotes time to reading his class notes and solving practice problems. His grade (G) is equal to G= 2.5R0.25P0.75, where R is the time he spends reading his notes and P the time he spends solving problems. If John has 4 hours to study every day, how many hours should he spend on reading his class notes and how many on practicing problems if he wants to maximize his grade in the upcoming exam?