At 10 30, Riordan left Town B for Town C, driving at a speed of 84 km/h. At 12 30, Harry also left Town B for Town C driving at a certain speed. Both of them did not change their speed throughout the journey. At 14 30, both of them passed a bakery that was 252 km away from Town C. How many minutes earlier did Harry reach Town C than Riordan?
Duration that Riordan travelled from 10 30 to 14 30 = 4 h
Distance that Riordan travelled
= 4 x 84
= 336 km
Distance between Town B and Town C
= 336 + 252
= 588 km
Since Harry passed the bakery at the same time as Riordan, it means that Harry travelled 336 km in 2 hours.
Harry's speed during the journey
= 336 ÷ 2
= 168 km/h
Duration that Harry took to reach Town C after passing the bakery
= 252 ÷ 168
= 1.5 h
Duration that Riordan took to reach Town C after passing the bakery
= 252 ÷ 84
= 3 h
Difference between the time they took to reach Town C
= 3 - 1.5
= 1.5 h
1 h = 60 min
1.5 h = 1.5 x 60 = 90 min
Harry reached Town C 90 minutes earlier than Riordan.
Answer(s): 90 min
