At 14 10, Oliver left Town C for Town D, driving at a speed of 84 km/h. At 16 10, Oscar also left Town C for Town D driving at a certain speed. Both of them did not change their speed throughout the journey. At 19 10, both of them passed a salon that was 168 km away from Town D. How many minutes earlier did Oscar reach Town D than Oliver?

Distance that Oliver travelled
= 5 x 84
= 420 km

Distance between Town C and Town D
= 420 + 168
= 588 km

Since Oscar passed the salon at the same time as Oliver, it means that Oscar travelled 420 km in 3 hours.

Oscar's speed during the journey
= 420 ÷ 3
= 140 km/h

Duration that Oscar took to reach Town D after passing the salon
= 168 ÷ 140
= 1.2 h

Duration that Oliver took to reach Town D after passing the salon
= 168 ÷ 84
= 2 h

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

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

Oscar reached Town D 48 minutes earlier than Oliver.

Answer(s): 48 min