Statement of Financial Position and Statement of Profit or Loss

This is one of the practice questions online from this website:

On 1 July 2012, a business had net assets of $23,000. At 30 June 2013, they had total assets of $34,000 and total liabilities of $8,000. During the year, the owner had $2,000 more capital and had taken drawings of $500 per month. What was the profit for the year ended 30 June 2013?

This is what I did:

($34,000-$23,000) = $2,000 + profit – ($500 x 12)
$11,000 = $2,000 + profit – $6,000
$11,000 = profit – $4,000
profit = $11,000 + $4,000
profit = $15,000

However, when I submitted the answer and I checked, it said that I was wrong and the answer was $7,000. When I saw how they worked the answer out, I saw that they reduced the liabilities worth $8,000 (given in question) from the closing net assets as of 30th June 2013 worth $34,000. I am kind of confused here; why do they decrease the liabilities from the net assets? What is the terminology and how does that work?