(15%) The yearly average solar flux incident on a horizontal surface in the United States is about 205 W/m. The average total energy demand in the United States is approximately 100 quads (100 x 1018) per year. Assuming an average efficiency of PV cells of 20% and a biomass conversion efficiency around 1%, estimate the percentage of land required to provide the energy of the country by these two renewable technologies, respectively. (The total land area of the United States is about 9.2 10 km)