At 14 40, Archie left Town P for Town Q, driving at a speed of 93 km/h. At 15 40, Bobby also left Town P for Town Q driving at a certain speed. Both of them did not change their speed throughout the journey. At 18 40, both of them passed a cinema that was 186 km away from Town Q. How many minutes earlier did Bobby reach Town Q than Archie?

Distance that Archie travelled
= 4 x 93
= 372 km

Distance between Town P and Town Q
= 372 + 186
= 558 km

Since Bobby passed the cinema at the same time as Archie, it means that Bobby travelled 372 km in 3 hours.

Bobby's speed during the journey
= 372 ÷ 3
= 124 km/h

Duration that Bobby took to reach Town Q after passing the cinema
= 186 ÷ 124
= 1.5 h

Duration that Archie took to reach Town Q after passing the cinema
= 186 ÷ 93
= 2 h

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

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

Bobby reached Town Q 30 minutes earlier than Archie.

Answer(s): 30 min