Official Solution: At 10:00 p.m., a cyclist is 10 miles from home on a straight road. From that time on, the cyclist continues riding farther from home at a constant speed of 3 minutes per mile, then turns around and rides back toward home at the same speed along the same road. If the cyclist must arrive back home at 10:48 p.m., how many additional miles can the cyclist travel away from home after 10:00 p.m. before turning around? A. 2
B. 3
C. 6
D. 9
E. 12
At 10:00 p.m., the cyclist is 10 miles from home. On the way back, riding those 10 miles at 3 minutes per mile will take 30 minutes. Since the cyclist must be home at 10:48 p.m., only 18 minutes remain for riding farther away and then returning to the 10-mile point. That gives 9 minutes out and 9 minutes back. At a pace of 3 minutes per mile, 9 minutes corresponds to 3 miles.
Answer: B