Question

With a height almost three times as tall as the Mount Everest, Mount _that stands on planet Mars is the tallest mountain peak in the Solar System​

Answer 1

Olympus Mons is a very large shield volcano on the planet Mars. The volcano has a height of over 21 km as measured by the Mars Orbiter Laser Altimeter. Olympus Mons is about two and a half times Mount Everest's height above sea level.
Discoverer: Mariner 9
Peak: 21,287.4 m (69,841 ft) above datum; 26 km (85,000 ft) local relief; 26 km (85,000 ft) above plains
Dimensions: Tallest planetary mountain in the Solar System