Time-apportioned interest on separate capital contributions Steps:

• Interest on initial capital for first 6 months: $50,000 × 10$2,500
• Interest on additional capital for second 6 months: $20,000 × 10$1,000
• Total interest: $2,500 +$1,000 = $3,500
• Net increase in current account (no drawings): $25,000 −$5,000 = $20,000
• X's share of residual profit (after interest): $20,000 −$3,500 = $16,500

Why C is correct:

• Residual profit is total profit after deducting interest on capital; X's share equals net current account increase minus time-apportioned interest on each contribution per partnership agreement.

Why the others are wrong:

• A: Assumes full-year interest on average capital ($60,000 × 10$6,000), yielding $14,000 (not an option, but close variant).
• B: Assumes full-year interest only on initial capital ($50,000 × 10$5,000), yielding $15,000.
• D: Assumes interest only on initial capital for half year ($2,500), yielding$17,500.

Final answer: C