At 13 50, Vaidev left Town E for Town F, driving at a speed of 72 km/h. At 14 50, Flynn also left Town E for Town F driving at a certain speed. Both of them did not change their speed throughout the journey. At 17 50, both of them passed a hypermart that was 144 km away from Town F. How many minutes earlier did Flynn reach Town F than Vaidev?

Distance that Vaidev travelled
= 4 x 72
= 288 km

Distance between Town E and Town F
= 288 + 144
= 432 km

Since Flynn passed the hypermart at the same time as Vaidev, it means that Flynn travelled 288 km in 3 hours.

Flynn's speed during the journey
= 288 ÷ 3
= 96 km/h

Duration that Flynn took to reach Town F after passing the hypermart
= 144 ÷ 96
= 1.5 h

Duration that Vaidev took to reach Town F after passing the hypermart
= 144 ÷ 72
= 2 h

Difference between the time they took to reach Town F
= 2 - 1.5
= 0.5 h

1 h = 60 min
0.5 h = 0.5 x 60 = 30 min

Flynn reached Town F 30 minutes earlier than Vaidev.

Answer(s): 30 min