Yuto and Riko went for a bike ride on the same path. When Riko left their house, Yuto was 5.25 miles along the path. If Yuto’s average speed was 0.25 miles per minute and Riko’s average speed was 0.35 miles per minute, then Riko will be behind Yuto when 0 ≤ t

Question

Yuto and Riko went for a bike ride on the same path. When Riko left their house, Yuto was 5.25 miles along the path. If Yuto’s average speed was 0.25 miles per minute and Riko’s average speed was 0.35 miles per minute, then Riko will be behind Yuto when 0 ≤ t < 52.5, where t is time in minutes. Explain what this solution means and why t cannot be less than zero.

Mercury · Answer

they define t as "time in minutes" so 0 ≤ t < 52.5 means that the time must be greater than/equal to 0, and less than 52.5.

as for why t is defined to be "not less than 0" ---> think about what it would mean if t *were* less than 0 (a.k.a negative). Does "negative time" mean anything?