Answer:
The Mariner Valley is longer than the Grand Canyon by 7.31 times.
Step-by-step explanation:
The Grand Canyon is approximately 29 kilometers long.
Mariner Valley is a canyon on Mars that is approximately 212 kilometers long.
Mariner Valley is longer than the Grand Canyon by [tex]\frac{212}{29}[/tex] =7.31 times
Hence, the Mariner Valley is longer than the Grand Canyon by 7.31 times.
