All you really have to do is divide 45719(Money made in a year) divided by 40 (hours per week). Or you can divide then multiply 1142.97 x 40 and you get 45719. Hope I could Help :D
First lets remove the initial fee 150 is how much she is charging you per hour. If each hour is 55, lets divide 150 by 55. She charged you for 2.7 hours (almost 3) of service