Final answer:
Grant walks 2 miles every day. The number of miles that Grant could NOT have walked after some number of days is 10.
Step-by-step explanation:
To find the miles that Grant could NOT have walked after some number of days, we need to find the multiples of 2 and eliminate any options that match.
Let's start by multiplying 2 by 1 to get 2 miles.
Next, we multiply 2 by 2 to get 4 miles.
Continuing this pattern, we find that multiplying 2 by 3 gives us 6 miles.
Finally, multiplying 2 by 4 gives us 8 miles.
From these calculations, we can see that 10 miles (option C) is not a multiple of 2, so it could NOT be the number of miles that Grant has walked after some number of days.