At 14 50, Valen left Town Y for Town Z, driving at a speed of 82 km/h. At 17 50, Riordan also left Town Y for Town Z driving at a certain speed. Both of them did not change their speed throughout the journey. At 20 50, both of them passed a salon that was 246 km away from Town Z. How many minutes earlier did Riordan reach Town Z than Valen?

Distance that Valen travelled
= 6 x 82
= 492 km

Distance between Town Y and Town Z
= 492 + 246
= 738 km

Since Riordan passed the salon at the same time as Valen, it means that Riordan travelled 492 km in 3 hours.

Riordan's speed during the journey
= 492 ÷ 3
= 164 km/h

Duration that Riordan took to reach Town Z after passing the salon
= 246 ÷ 164
= 1.5 h

Duration that Valen took to reach Town Z after passing the salon
= 246 ÷ 82
= 3 h

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

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

Riordan reached Town Z 90 minutes earlier than Valen.

Answer(s): 90 min