Answer:
42
Step-by-step explanation:
you're traveling 12 miles every hour.
12 * 3 = 36
in 3 hours you will have traveled 36 miles.
your friend is traveling 2 miles every hour.
2 * 3 = 6
In 3 hours they will have traveled 6 miles
The distance between you is the miles you traveled + the miles they traveled.
36 + 6 = 42
You will be 42 miles apart after 3 hours