There are 21 marbles in a blue jar. the blue jars has 3 times as many marbles as a red jar. let m be the number of marbles in the red jar

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. ?