Using the accounting equation

Question

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At January 01, 20X9, Robert’s business assets were valued at $ 36,000 and his liabilities amounted to $ 2400. At 31st Dec, 20X9, Robert’s assets amounted to $ 57,000 and included his private car which he had brought into the business on 1st Nov when it was valued at $9000. His trade receivables at 31st December totaled $ 17,000. His drawings during the year were $ 27,000.

Required

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Calculate profit for the year ended 31st December 20X9.

Accounting year – 01-01-20X9 to 31-12-20X9
Opening assets – $ 36,000
Opening liabilities – $ 2400
Opening capital = $ 36,000 – $ 2400 = $ 33,600

Closing capital = $ 57,000 – $ 17,000 = $ 40,000

Using accounting equation,

Profit = closing capital – opening capital – additional capital + drawings

Profit = $ 40,000 – $ 33,600 – $ 9,000 + $ 27,000

Profit = $ 24,400.

CONFUSION

In this answer, I am confused about calculation for closing capital.

A) Should not we include receivables because receivables are current assets and closing capital = closing assets Less closing liabilities??

B) Should not we subtract $9000 worth of private car introduced in business from closing capital figure?? like $ 57,000 – $ 9,000 = $ 48,000 (closing capital)

Thank you!