At 12 35, Xavier left Town F for Town G, driving at a speed of 64 km/h. At 13 35, Vaidev also left Town F for Town G driving at a certain speed. Both of them did not change their speed throughout the journey. At 17 35, both of them passed a bistro that was 128 km away from Town G. How many minutes earlier did Vaidev reach Town G than Xavier?

Distance that Xavier travelled
= 5 x 64
= 320 km

Distance between Town F and Town G
= 320 + 128
= 448 km

Since Vaidev passed the bistro at the same time as Xavier, it means that Vaidev travelled 320 km in 4 hours.

Vaidev's speed during the journey
= 320 ÷ 4
= 80 km/h

Duration that Vaidev took to reach Town G after passing the bistro
= 128 ÷ 80
= 1.6 h

Duration that Xavier took to reach Town G after passing the bistro
= 128 ÷ 64
= 2 h

Difference between the time they took to reach Town G
= 2 - 1.6
= 0.4 h

1 h = 60 min
0.4 h = 0.4 x 60 = 24 min

Vaidev reached Town G 24 minutes earlier than Xavier.

Answer(s): 24 min