At 11 10, Glen left Town C for Town D, driving at a speed of 99 km/h. At 12 10, Zeph also left Town C for Town D driving at a certain speed. Both of them did not change their speed throughout the journey. At 15 10, both of them passed a florist that was 198 km away from Town D. How many minutes earlier did Zeph reach Town D than Glen?
Duration that Glen travelled from 11 10 to 15 10 = 4 h
Distance that Glen travelled
= 4 x 99
= 396 km
Distance between Town C and Town D
= 396 + 198
= 594 km
Since Zeph passed the florist at the same time as Glen, it means that Zeph travelled 396 km in 3 hours.
Zeph's speed during the journey
= 396 ÷ 3
= 132 km/h
Duration that Zeph took to reach Town D after passing the florist
= 198 ÷ 132
= 1.5 h
Duration that Glen took to reach Town D after passing the florist
= 198 ÷ 99
= 2 h
Difference between the time they took to reach Town D
= 2 - 1.5
= 0.5 h
1 h = 60 min
0.5 h = 0.5 x 60 = 30 min
Zeph reached Town D 30 minutes earlier than Glen.
Answer(s): 30 min
