At 11 25, Luis left Town P for Town Q, driving at a speed of 78 km/h. At 13 25, Justin also left Town P for Town Q driving at a certain speed. Both of them did not change their speed throughout the journey. At 15 25, both of them passed a museum that was 234 km away from Town Q. How many minutes earlier did Justin reach Town Q than Luis?
Duration that Luis travelled from 11 25 to 15 25 = 4 h
Distance that Luis travelled
= 4 x 78
= 312 km
Distance between Town P and Town Q
= 312 + 234
= 546 km
Since Justin passed the museum at the same time as Luis, it means that Justin travelled 312 km in 2 hours.
Justin's speed during the journey
= 312 ÷ 2
= 156 km/h
Duration that Justin took to reach Town Q after passing the museum
= 234 ÷ 156
= 1.5 h
Duration that Luis took to reach Town Q after passing the museum
= 234 ÷ 78
= 3 h
Difference between the time they took to reach Town Q
= 3 - 1.5
= 1.5 h
1 h = 60 min
1.5 h = 1.5 x 60 = 90 min
Justin reached Town Q 90 minutes earlier than Luis.
Answer(s): 90 min
