At 14 15, Ryan left Town W for Town X, driving at a speed of 80 km/h. At 17 15, Riordan also left Town W for Town X driving at a certain speed. Both of them did not change their speed throughout the journey. At 20 15, both of them passed a mosque that was 240 km away from Town X. How many minutes earlier did Riordan reach Town X than Ryan?

Distance that Ryan travelled
= 6 x 80
= 480 km

Distance between Town W and Town X
= 480 + 240
= 720 km

Since Riordan passed the mosque at the same time as Ryan, it means that Riordan travelled 480 km in 3 hours.

Riordan's speed during the journey
= 480 ÷ 3
= 160 km/h

Duration that Riordan took to reach Town X after passing the mosque
= 240 ÷ 160
= 1.5 h

Duration that Ryan took to reach Town X after passing the mosque
= 240 ÷ 80
= 3 h

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

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

Riordan reached Town X 90 minutes earlier than Ryan.

Answer(s): 90 min