Philip Minghetti, age 10, of Tucson, Arizona, for his question:

Exactly how high is the earth's highest mountain?

This lofty peak is Mount Everest in the Himalaya Mountains of Asia. Only a handful of bold mountaineers have scaled to.the top of its icy slopes. But geographers do not have to scramble to the top of a peak to measure its altitude above sea level. The world's highest mountain is named for Sir George Everest, one of the first to survey its lofty peak. Sir George was surveyor general of India in the 1800's and he figured that the top of his mountain stood 29,141 feet above sea level. A British government survey in the 19th century figured that it was only 29,002 feet tall and later estimates also suggest that Everest's figure was about 100 feet too high.

An Indian survey of 1956 estimated the altitude of the peak as 29,0281eet. This is the most widely accepted figure. In surveying such a height, exact precision is almost impossible. What's more, the weathery pinnacle tends to lose or gain a few feet of icy snow with the changing seasons. In any case, we can take its altitude to be about.29,000 feet, or 5 1/2 miles high.