At 11 40, Zane left Town M for Town N, driving at a speed of 72 km/h. At 12 40, Ahmad also left Town M for Town N driving at a certain speed. Both of them did not change their speed throughout the journey. At 15 40, both of them passed a cafe that was 144 km away from Town N. How many minutes earlier did Ahmad reach Town N than Zane?

Distance that Zane travelled
= 4 x 72
= 288 km

Distance between Town M and Town N
= 288 + 144
= 432 km

Since Ahmad passed the cafe at the same time as Zane, it means that Ahmad travelled 288 km in 3 hours.

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

Duration that Ahmad took to reach Town N after passing the cafe
= 144 ÷ 96
= 1.5 h

Duration that Zane took to reach Town N after passing the cafe
= 144 ÷ 72
= 2 h

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

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

Ahmad reached Town N 30 minutes earlier than Zane.

Answer(s): 30 min