A local hamburger sold a combined total of 600 hamburgers and cheeseburgers on Monday. There were 50 more cheeseburgers sold than hamburgers How many hamburgers were sold on Monday ?

The salesperson earns a 5% commission on the first $5,000 she has in sales. the salesperson earns a 7.5% commission on the amount of her sales that are greater than $5,000. this month the sales person had $8,000 in sales. what amount of commission, in dollars, did she earn?