In arizona in early september, a balloonists decided he wanted to actually fly just holding onto giant helium inflated balloons. The man and the balloons (all spheres) had to be less dense than the air (whose density is 1.28 E-3 gm/ml) in order for the man to float. The man weighed in at 80,000 gm and his gear was 16,500 gm. Each balloon was 140 cm in diameter. Find the number of balloons needed to lift our high flyer. URGENT!!!