pls help

Bolton Store uses a PERPETUAL inventory system. Bolton engaged in the following transactions during April: April 12 Purchased $15,000 in merchandise subject to terms of 2/10, n/30. April 13 Received a billing from Orange Freight Lines for $300 for the April 12 purchase. Returned $1,000 of merchandise from the April 12 purchase. April 20 Paid balances due from April 12 purchase and April 13 freight. Required: Show computations. a Prepare journal entries to record the above transactions using the gross method. b) Prepare journal entries to record the above transactions using the net method