Answer:
52 minutes and 30 seconds
Explanation:
You know that Yuto has ridden for 5.25 miles when Riko left their house and you need to know and what time they will be together:
Then you can say that:
5.25 miles+(yutos speed)*t= (Rikos speed)*t
when t=Time in minutes when they will be together
5.25 miles+(0.25miles/min)*t= (0,35miles/min)*t
5.25miles=(0.35miles/min-0.25miles/min)*t
5.25miles/(0.35miles/min-0.25miles/min)=t
t=52.5 min =52 minutes and 30 seconds