Trend Company on April 1, 2019 sold to its customer, Primary Company, 400 drums of lubricating oil for $40 per drum on 2/10/net 30 terms. The cost of each drum is $20. On April 5 Primary returned 20 drums to Trend for credit because its lubricating oil inventory was too high. Primary paid the total amount owing to Trend for the lubricating oil transaction on April 8. Assuming that Trend records its sales and receivable on a gross basis what entries should Trend make on April 1, April 5 and April 8 for the lubricating oil transactions?