James paints a 20 ft by 15 ft mural. It takes him 20 minutes to paint 1 square foot and he charges $150 per hour. How much does he charge to paint the mural? Let's think first. Chain of thought:
The mural is 20 * 15 = 300 square feet. So it takes him 300 * 20 = 6000 minutes. So he paints it in 6000 / 60 = 100 hours. That means he charges 100 * 150 = $15000.
Therefore, the answer is 15000.