The question is missing some parts. But the problem here is asking the journal entries for April 2, May 3, and June 1.
  
 Apr 2:
 Debit Accounts Receivable 1,200
 Credit Sales Revenue 1,200
  
 May 3:
 Debit Cash 600
 Credit Accounts Receivable 600
  
 June 1
 Debit Accounts Receivable 18
 Credit Interest Revenue 18
 Computation: 1200 – 600 = 600 * 0.03