At 13 35, Jeremy left Town C for Town D, driving at a speed of 60 km/h. At 16 35, Ethan also left Town C for Town D driving at a certain speed. Both of them did not change their speed throughout the journey. At 18 35, both of them passed a library that was 240 km away from Town D. How many minutes earlier did Ethan reach Town D than Jeremy?
Duration that Jeremy travelled from 13 35 to 18 35 = 5 h
Distance that Jeremy travelled
= 5 x 60
= 300 km
Distance between Town C and Town D
= 300 + 240
= 540 km
Since Ethan passed the library at the same time as Jeremy, it means that Ethan travelled 300 km in 2 hours.
Ethan's speed during the journey
= 300 ÷ 2
= 150 km/h
Duration that Ethan took to reach Town D after passing the library
= 240 ÷ 150
= 1.6 h
Duration that Jeremy took to reach Town D after passing the library
= 240 ÷ 60
= 4 h
Difference between the time they took to reach Town D
= 4 - 1.6
= 2.4 h
1 h = 60 min
2.4 h = 2.4 x 60 = 144 min
Ethan reached Town D 144 minutes earlier than Jeremy.
Answer(s): 144 min
