Steve needs to be at a meeting in 30 minutes. If he drives at 30mph, he'll be late. If he drives at 40mph, he'll be a few minutes early. Which of these distances is possibly the distance from his house to his meeting?

At 30mph, Steve would need to travel more than 15 miles to be late (since 15 miles takes exactly 30 minutes). At 40mph, he would need to travel less than 20 miles to arrive early (since 20 miles takes exactly 30 minutes). 16 miles is the only option satisfying 15 < d < 20: at 30mph it takes 32 minutes (late), at 40mph it takes 24 minutes (early).