In the purchase book all the credit purchases of goods in which the business deal are recorded. Periodical total of purchases is posted to the debit side of the Purchase A/c. From the purchase book each individual supplier's account (creditor) is credited. In this question the creditor's account will be credited by $250 instead of $25, hence an extra credit of Rs.225 to the supplier. It will not impact the profit or loss of the business in any way.