The UK currently has a progressive income tax system. The rules are as follows: Any earnings under 11,500 GBP are taxed at 0%. Any earnings between 11,500 GBP and 33,500 GBP are taxed at 20%. Any earnings between 33,500 GBP and 150,000 GBP are taxed at 40%. Any earnings above 150,000 GBP are taxed at 50%. A person earns 50,000 GBP gross. How much tax do they pay? Round your answer to the nearest GBP.