At 10 35, Ryan left Town W for Town X, driving at a speed of 84 km/h. At 11 35, Ian also left Town W for Town X driving at a certain speed. Both of them did not change their speed throughout the journey. At 14 35, both of them passed a boutique that was 168 km away from Town X. How many minutes earlier did Ian reach Town X than Ryan?

Distance that Ryan travelled
= 4 x 84
= 336 km

Distance between Town W and Town X
= 336 + 168
= 504 km

Since Ian passed the boutique at the same time as Ryan, it means that Ian travelled 336 km in 3 hours.

Ian's speed during the journey
= 336 ÷ 3
= 112 km/h

Duration that Ian took to reach Town X after passing the boutique
= 168 ÷ 112
= 1.5 h

Duration that Ryan took to reach Town X after passing the boutique
= 168 ÷ 84
= 2 h

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

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

Ian reached Town X 30 minutes earlier than Ryan.

Answer(s): 30 min