Answer:
km
Explanation:
Given : The diameter of Mars is about
.
It can be rewrite as

[∵
]
The diameter of Earth is about

It can be rewrite as

[∵
]
Clearly, 12,763> 6,800
Now, the difference in the diameter of Earth and Mars will be :-

Which can written as

Hence, Earth's diameter is
km greater than Mars.