Halleys Comet. Rmin =8.9 x 10^10 m

Period of orbit = 2.4 x 10^9 sec
1)What is value of K for Halley's comet?
2)Whats the average radius of Halleys comet orbit?
3)What is value of the aphelion(Rmax) for halley's comet.(Rmin is perihelion. Recall Rave= [{Rmin +Rmax}/2]
4) what is Rmax/Rmin.