Distance to PET = (D x H)/(O + H)
D = 3016nm
O = 480 - 90 = 390kts
H = 480 + 75 = 555ktd
O + H = 945
Distance to PET = (3016 x 555)/945 = 1771.3nm
177.3nm at 390kts = 4hrs 32min
Depart at 13:20 + 4:32 = ETA PET 17:52