Cate earns $20 per hour, so we are looking for the number of hours: 20x
Cate pays $1.50 for the bus each way, implying that she rides the bus twice in a day: 3
Cate must end up with $117: 117
117 = 20x + 3
114 = 20x
x = 5.7 hours
Cate must work 5.7 hours to end up with $117.
Hope this helps!! :)