At 12 40, Perry left Town W for Town X, driving at a speed of 72 km/h. At 14 40, Mark also left Town W for Town X driving at a certain speed. Both of them did not change their speed throughout the journey. At 17 40, both of them passed a mall that was 144 km away from Town X. How many minutes earlier did Mark reach Town X than Perry?

Distance that Perry travelled
= 5 x 72
= 360 km

Distance between Town W and Town X
= 360 + 144
= 504 km

Since Mark passed the mall at the same time as Perry, it means that Mark travelled 360 km in 3 hours.

Mark's speed during the journey
= 360 ÷ 3
= 120 km/h

Duration that Mark took to reach Town X after passing the mall
= 144 ÷ 120
= 1.2 h

Duration that Perry took to reach Town X after passing the mall
= 144 ÷ 72
= 2 h

Difference between the time they took to reach Town X
= 2 - 1.2
= 0.8 h

1 h = 60 min
0.8 h = 0.8 x 60 = 48 min

Mark reached Town X 48 minutes earlier than Perry.

Answer(s): 48 min