At 12 55, Tom left Town C for Town D, driving at a speed of 69 km/h. At 14 55, Justin also left Town C for Town D driving at a certain speed. Both of them did not change their speed throughout the journey. At 16 55, both of them passed a clinic that was 207 km away from Town D. How many minutes earlier did Justin reach Town D than Tom?
Duration that Tom travelled from 12 55 to 16 55 = 4 h
Distance that Tom travelled
= 4 x 69
= 276 km
Distance between Town C and Town D
= 276 + 207
= 483 km
Since Justin passed the clinic at the same time as Tom, it means that Justin travelled 276 km in 2 hours.
Justin's speed during the journey
= 276 ÷ 2
= 138 km/h
Duration that Justin took to reach Town D after passing the clinic
= 207 ÷ 138
= 1.5 h
Duration that Tom took to reach Town D after passing the clinic
= 207 ÷ 69
= 3 h
Difference between the time they took to reach Town D
= 3 - 1.5
= 1.5 h
1 h = 60 min
1.5 h = 1.5 x 60 = 90 min
Justin reached Town D 90 minutes earlier than Tom.
Answer(s): 90 min