Final answer:
The hiker will not have hard-boiled eggs for breakfast because the boiling point of water at high altitudes is lower than at sea level.
Step-by-step explanation:
Due to the lower boiling point of water at high altitudes, the hiker will not be able to achieve hard-boiled eggs by leaving the egg in boiling water longer. The boiling point of water decreases as altitude increases, so at the base camp of Mount Everest where the altitude is 5,300 meters, the boiling point of water is lower than at sea level. Therefore, the water will not reach the temperature necessary to cook the egg to a hard-boiled consistency.