Garber plumbers offers a 20% trade discount when providing $2,000 or more of plumbing services to its customers. in march 2021, garber provided $4,000 of plumbing services to red oak inc., and $1,500 of services to cyril inc. each of these customers was granted credit terms of 2/10, net 30. if both customers paid for the plumbing services within the discount period, what was the net revenues amount for these two transactions