Conversation so far:
who is the first person to reach the top of mount everest
New Zealander Edmund Hillary and Nepalese Tenzing Norgay were the first people to ever reach the summit of Mount Everest.
when did Edmund Hillary and Tenzing Norgay reach the top of mount everest
New Zealander Edmund Hillary and Nepalese Tenzing Norgay reached the summit at 11:30 a.m. on May 29, 1953.

Question: how tall is the mountain
Self-contained rewrite: how tall is mount everest