Concept:A trial balance lists all debit and credit balances to confirm they are equal.Explanation:Debit balances: Light expenses N400; Purchases N3,000; Debtors N50.Total debits =N400+N3,000+N50=N3,450.Credit balances: Sales N1,200; Creditors N2,250.Total credits =N1,200+N2,250=N3,450.Therefore, the trial balance total is N3,450.Answer:N3,450