My cousin Alyssa works at a gas station. Initially she was paid $10 per hour and requested to only work 25 hours per week. After 1 year on the job she got a pay raise to $12 per hour and requested to work 35 hours per week. After 2 years on the job, she got a pay raise to $20 per hour and requested to work 30 hours per week.

a. Why does Alyssa want to work more hours when she receives a raise from $10 per hour to $12 per hour?

b. Why does Alyssa want to work less hours when she receives a raise from $12 per hour to $20 per hour?