General chemistry

Question

An ideal gas sample had a volume of one liter at sea-level conditions of 1.01bar and 18•c. As the gas enters the atmosphere,500km above the sea-level,the volume increased to 3.5×10¹¹litres at a pressure of 1.5×10¹¹ bar. What is the temperature of the gas at this altitude?

Answer 1

How can the pressure be 1.5x10¹¹ bar at 500 km above sea level? As one rises into the atmosphere, the pressure will DECREASE, not increase^.