Alhaji Musa, a sole trader, received a cheque of ₦450,000 from Debtor A in full settlement of an invoice of ₦500,000. The ₦50,000 discount allowed was recorded only in the discount allowed account and nowhere else. Which book of prime entry was omitted in recording the receipt?

The receipt of the cheque should first be recorded in the cash book (a book of prime entry), which also serves as both a book of original entry and part of the double entry system. The cash book captures the ₦450,000 debit to bank and the ₦50,000 discount allowed, with the full ₦500,000 credit to the debtor's account. Omitting the cash book means the receipt was never entered in any book of prime entry for the cash transaction.