Waterway Industries uses the perpetual inventory and the gross method. On March 1, it purchased $70000 of inventory, terms 2/10, n/30. On March 3, Waterway returned goods that cost $7000. On March 9, Waterway paid the supplier. On March 9, Waterway should credit inventory for $1260. purchase discounts for $1260. purchase discounts for $1400. inventory for $1400