If Riko will be behind Yuto from the time she leaves her house until 52.5 minutes into her ride, we can represent the situation using the following inequality:
0 ≤ t ≤ 52.5
Here, t represents the time in minutes that has elapsed since Riko left her house. We know that Riko will be behind Yuto for this entire period, so we don't need to worry about their relative positions at specific times within this interval.
The inequality specifies that time cannot be negative, which makes sense since Riko cannot travel back in time to leave her house before she actually does. The upper limit of 52.5 represents the time at which Riko will have traveled 52.5 minutes into her ride, and at this point, Yuto will be ahead of her.