Josefina works between 10 and 30 hours per week at a pizzeria. she earns $6.50 an hour, but can earn tips when she delivers pizza.
a) write a system of inequalitites to represent the dollars 'd' she could earn for 'h' hours in a week.
b) if josefina recieved $17.50 in tips and earned a total of $180 for the week, how many hours did she work?

There are two major tests of readiness for college: the act and the sat. act scores are reported on a scale from 1 to 36. the distribution of act scores in recent years has been roughly normal with mean µ = 20.9 and standard deviation s = 4.8. sat scores are reported on a scale from 400 to 1600. sat scores have been roughly normal with mean µ = 1026 and standard deviation s = 209. reports on a student's act or sat usually give the percentile as well as the actual score. the percentile is just the cumulative proportion stated as a percent: the percent of all scores that were lower than this one. tanya scores 1260 on the sat. what is her percentile (± 1)?