On March $1,$ Bates Board Shop sells $300$ surfboards to a local lifeguard station at a sales price of $$400$ per board. The cost to Bates is $$140$ per board. The terms of the sale are $3/15,$ n$/30,$ with an invoice date of March $1.$

Create the journal entries for Bates to recognize the following transactions:

a$.$ the initial sale

b$.$ the subsequent customer payment on March $10$