Hector must complete 40 community service hours in order to graduate from the eighth grade. so far, he has completed 1/5 of his hours by working at a food bank and 10% of his hours volunteering at a hospital. which expression can hector use to calculate the number of community service hours he has left to complete? a) 40 (4/5) + 40 (0.9 b) 40 (1/5) +40(0.1) c) 40 (1/5 + 0.1) d) 40- ((40 x 1/5) + ( 0.1 x 40))