At a certain university, students wishing to enroll in calculus must take a placement exam. The exam scores are normally distributed with mean of 225 and a standard deviation of 19. Students who score at the 60th percentile are eligible to enroll in precalculus. Students who score at the 80th percentile are eligible to enroll in calculus.

a) What is the minimum score required to enroll in precalculus?

b) What is the minimum score required to enroll in calculus?