An english instructor asserted that students' test grades are directly proportional to the amount of time spent studying. lisa studies 6hr for a particular test and gets a score of 73. at this rate, how many hours would she have had to study to get a score of 91?

It took alice 5 5/6 hours to drive to her grandparents' house for . on the way home, she ran into traffic and it took her 7 3/8 hours. how much longer did the return trip take? write your answer as a proper fraction or mixed number in simplest form. the trip home took __hours longer. ?