At 10 55, Liam left Town T for Town U, driving at a speed of 64 km/h. At 13 55, Valen also left Town T for Town U driving at a certain speed. Both of them did not change their speed throughout the journey. At 15 55, both of them passed a mall that was 256 km away from Town U. How many minutes earlier did Valen reach Town U than Liam?

Distance that Liam travelled
= 5 x 64
= 320 km

Distance between Town T and Town U
= 320 + 256
= 576 km

Since Valen passed the mall at the same time as Liam, it means that Valen travelled 320 km in 2 hours.

Valen's speed during the journey
= 320 ÷ 2
= 160 km/h

Duration that Valen took to reach Town U after passing the mall
= 256 ÷ 160
= 1.6 h

Duration that Liam took to reach Town U after passing the mall
= 256 ÷ 64
= 4 h

Difference between the time they took to reach Town U
= 4 - 1.6
= 2.4 h

1 h = 60 min
2.4 h = 2.4 x 60 = 144 min

Valen reached Town U 144 minutes earlier than Liam.

Answer(s): 144 min