At 11 50, Will left Town G for Town H, driving at a speed of 78 km/h. At 12 50, Fred also left Town G for Town H driving at a certain speed. Both of them did not change their speed throughout the journey. At 15 50, both of them passed a boutique that was 156 km away from Town H. How many minutes earlier did Fred reach Town H than Will?

Distance that Will travelled
= 4 x 78
= 312 km

Distance between Town G and Town H
= 312 + 156
= 468 km

Since Fred passed the boutique at the same time as Will, it means that Fred travelled 312 km in 3 hours.

Fred's speed during the journey
= 312 ÷ 3
= 104 km/h

Duration that Fred took to reach Town H after passing the boutique
= 156 ÷ 104
= 1.5 h

Duration that Will took to reach Town H after passing the boutique
= 156 ÷ 78
= 2 h

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

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

Fred reached Town H 30 minutes earlier than Will.

Answer(s): 30 min