(a) Why are many accounting systems designed with a purchases ledger (creditors ledger) control account, as well as with a purchases ledger (creditors ledger)?

(b) The following errors have been discovered:

(i) An invoice for £654 has been entered in the purchases day book as £456;

(ii) A prompt payment discount of £100 from a creditor had been completely omitted from the accounting records;

(iii) Purchases of £250 had been entered on the wrong side of a supplier’s account in the purchases ledger;

(iv) No entry had been made to record an agreement to contra an amount owed to X of £600 against an amount owed by X of £400;

(v) A credit note for £60 had been entered as if it was an invoice. State the numerical effect on the purchases ledger control account balance of correcting each of these items (treating each item separately).

(c) Information technology and computerised systems are rapidly increasing in importance in data recording. Do you consider that this trend will eventually remove the need for control accounts to be incorporated in the design of accounting systems? Explain your answer briefly.