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))