At 11 45, Elijah left Town D for Town E, driving at a speed of 90 km/h. At 12 45, Ken also left Town D for Town E driving at a certain speed. Both of them did not change their speed throughout the journey. At 15 45, both of them passed a florist that was 180 km away from Town E. How many minutes earlier did Ken reach Town E than Elijah?

Distance that Elijah travelled
= 4 x 90
= 360 km

Distance between Town D and Town E
= 360 + 180
= 540 km

Since Ken passed the florist at the same time as Elijah, it means that Ken travelled 360 km in 3 hours.

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

Duration that Ken took to reach Town E after passing the florist
= 180 ÷ 120
= 1.5 h

Duration that Elijah took to reach Town E after passing the florist
= 180 ÷ 90
= 2 h

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

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

Ken reached Town E 30 minutes earlier than Elijah.

Answer(s): 30 min