Like water in the ocean, air in the atmosphere exerts pressure that increases with depth. Most gas molecules in the atmosphere are pulled close to Earth’s surface by gravity. As a result, air pressure decreases quickly at lower altitudes and then more slowly at higher altitudes. This is illustrated in Figure below . Air pressure is greatest at sea level, where the depth of the atmosphere is greatest. At higher altitudes, the pressure is less because the depth of the atmosphere is less. For example, on top of Mount Everest, the tallest mountain on Earth, air pressure is only about one-third of the pressure at sea level. At such high altitudes, low air pressure makes it hard to breathe and is dangerous to human health.
Context:
Derek is going on a hiking trip with his friends. Before they go they have to decide which mountain they want to go hiking on. Mount Joral is a mountain with a reasonably low altitude. Mount Rook is very high with a much higher altitude. While they are deciding Derek's best friend, Adam, reminds him that he has trouble breathing sometimes.
Q: Which mountain should Derek and his friends climb given they are concerned for Adam?