At 10 30, David left Town H for Town J, driving at a speed of 71 km/h. At 13 30, George also left Town H for Town J driving at a certain speed. Both of them did not change their speed throughout the journey. At 16 30, both of them passed a mosque that was 213 km away from Town J. How many minutes earlier did George reach Town J than David?

Distance that David travelled
= 6 x 71
= 426 km

Distance between Town H and Town J
= 426 + 213
= 639 km

Since George passed the mosque at the same time as David, it means that George travelled 426 km in 3 hours.

George's speed during the journey
= 426 ÷ 3
= 142 km/h

Duration that George took to reach Town J after passing the mosque
= 213 ÷ 142
= 1.5 h

Duration that David took to reach Town J after passing the mosque
= 213 ÷ 71
= 3 h

Difference between the time they took to reach Town J
= 3 - 1.5
= 1.5 h

1 h = 60 min
1.5 h = 1.5 x 60 = 90 min

George reached Town J 90 minutes earlier than David.

Answer(s): 90 min