Tim started from his home and drove one and one-half hours to meet his uncle with whom he spent three and one-quarter hours. Then he drove 1/5 of an hour to see his grandmother and spent two and one-half hours with her. Finally, he drove back home in one and three-fifths hours. Altogether, how many hours did he spend outside before returning home?
1 1/2 + 3 1/4 + 1/5 + 2 1/2 + 1 3/5 = ____
use a common denominator of 20 to add all those fractions.