Sale of principal residence. Patricia bought a house on January $1,2010,$ for $$470,000.$ She immediately started using the house as her principal residence. She married Peter on January $1,2018,$ and he immediately moved into the house. It was their principal residence until Patricia sold it on June $30,2019,$ for $$820,000.$ No unforeseen circumstances were involved. How much capital gain did they have to report on their joint return for this sale?