At 13 30, Ethan left Town C for Town D, driving at a speed of 75 km/h. At 15 30, Ryan also left Town C for Town D driving at a certain speed. Both of them did not change their speed throughout the journey. At 17 30, both of them passed a florist that was 225 km away from Town D. How many minutes earlier did Ryan reach Town D than Ethan?

Distance that Ethan travelled
= 4 x 75
= 300 km

Distance between Town C and Town D
= 300 + 225
= 525 km

Since Ryan passed the florist at the same time as Ethan, it means that Ryan travelled 300 km in 2 hours.

Ryan's speed during the journey
= 300 ÷ 2
= 150 km/h

Duration that Ryan took to reach Town D after passing the florist
= 225 ÷ 150
= 1.5 h

Duration that Ethan took to reach Town D after passing the florist
= 225 ÷ 75
= 3 h

Difference between the time they took to reach Town D
= 3 - 1.5
= 1.5 h

1 h = 60 min
1.5 h = 1.5 x 60 = 90 min

Ryan reached Town D 90 minutes earlier than Ethan.

Answer(s): 90 min