1. Amount Due on First and Final Call: Remaining balance = ₹ 12 (total) - ₹ 7 (application and allotment) = ₹ 5. 2. Forfeited Shares: Quantity of shares forfeited = 1,000. 3. Calculation of Unpaid Sum: Aggregate unpaid sum = \( 1,000 \times ₹ 5 = ₹ 5,000. \) 4. Accounting for Calls in Arrears: Upon share forfeiture, the outstanding sum is credited to the Calls in Arrears Account: \[ \text{Calls in Arrears Account Credited} = ₹ 5,000. \]