Determine net income for the period if beginning owner's equity is $20,000, cash withdrawals by the owner amount to $7,000, and ending owner's equity is $37,000

Hi!
Take the opening balance of R20000 subtract the withdrawals by the owner R7000.then you would be having R13000.having R13000,how much would you need to add so that the amount becomes R37000? That is R20000-R7000+?=37000.My method is correct however I'm using my mind calculating the amount represented by the question mark. The question mark represents your net income. Your net income for the period is R24000