At 13 45, Valen left Town Q for Town R, driving at a speed of 85 km/h. At 15 45, Zane also left Town Q for Town R driving at a certain speed. Both of them did not change their speed throughout the journey. At 17 45, both of them passed a park that was 255 km away from Town R. How many minutes earlier did Zane reach Town R than Valen?

Distance that Valen travelled
= 4 x 85
= 340 km

Distance between Town Q and Town R
= 340 + 255
= 595 km

Since Zane passed the park at the same time as Valen, it means that Zane travelled 340 km in 2 hours.

Zane's speed during the journey
= 340 ÷ 2
= 170 km/h

Duration that Zane took to reach Town R after passing the park
= 255 ÷ 170
= 1.5 h

Duration that Valen took to reach Town R after passing the park
= 255 ÷ 85
= 3 h

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

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

Zane reached Town R 90 minutes earlier than Valen.

Answer(s): 90 min