At 10 10, Jack left Town N for Town P, driving at a speed of 69 km/h. At 12 10, Mark also left Town N for Town P driving at a certain speed. Both of them did not change their speed throughout the journey. At 15 10, both of them passed a school that was 138 km away from Town P. How many minutes earlier did Mark reach Town P than Jack?

Distance that Jack travelled
= 5 x 69
= 345 km

Distance between Town N and Town P
= 345 + 138
= 483 km

Since Mark passed the school at the same time as Jack, it means that Mark travelled 345 km in 3 hours.

Mark's speed during the journey
= 345 ÷ 3
= 115 km/h

Duration that Mark took to reach Town P after passing the school
= 138 ÷ 115
= 1.2 h

Duration that Jack took to reach Town P after passing the school
= 138 ÷ 69
= 2 h

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

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

Mark reached Town P 48 minutes earlier than Jack.

Answer(s): 48 min