At 14 35, Bryan left Town Y for Town Z, driving at a speed of 60 km/h. At 17 35, Michael also left Town Y for Town Z driving at a certain speed. Both of them did not change their speed throughout the journey. At 20 35, both of them passed a clinic that was 180 km away from Town Z. How many minutes earlier did Michael reach Town Z than Bryan?

Distance that Bryan travelled
= 6 x 60
= 360 km

Distance between Town Y and Town Z
= 360 + 180
= 540 km

Since Michael passed the clinic at the same time as Bryan, it means that Michael travelled 360 km in 3 hours.

Michael's speed during the journey
= 360 ÷ 3
= 120 km/h

Duration that Michael took to reach Town Z after passing the clinic
= 180 ÷ 120
= 1.5 h

Duration that Bryan took to reach Town Z after passing the clinic
= 180 ÷ 60
= 3 h

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

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

Michael reached Town Z 90 minutes earlier than Bryan.

Answer(s): 90 min