Answer:
45
Explanation:
I love math, so this was fun! First, we need to know how long it would take him to walk 1 mile. We know it took 12 minutes to walk 3/4 of a mile, so we just need to figure out how long each quater is. For this problem, each quarter of a mile is 3 minutes, and so we just need to multiply that by 4. then, we know it would take him 15 mintues to walk a mile. Then, just multiply that by 3! Hope this helps, sorry I can't spell :)