If A paid a firm expense from personal funds and the transaction was not recorded in the firm's books, what will be the effect on A's account?

Correct answer: It will be credited

A paid a firm expense from personal funds, so the firm owes A. Therefore A's account is credited (recorded as a liability to the partner — usually current or payable to partner). The common wrong choice 'debited' would apply only if the firm itself had paid A. Exam tip: first ask who paid and whether the firm recorded it; if partner pays firm expense, credit the partner; if firm pays partner, debit the partner.