Daedalus and his son icarus are building wings to fly home. Daedalus's wigs each weigh 2 kg,and Icarus wings each weigh 1/2 as much. Their dog Philo wings weigh 1/2 as much as Icarus's wings. Daedalus,icarus, and Philo used 2 feathers for each gram of wing. How many feathers did they use in all?

Answer :