At 13 20, Howard left Town B for Town C, driving at a speed of 81 km/h. At 15 20, Brandon also left Town B for Town C driving at a certain speed. Both of them did not change their speed throughout the journey. At 17 20, both of them passed a grocery store that was 243 km away from Town C. How many minutes earlier did Brandon reach Town C than Howard?

Distance that Howard travelled
= 4 x 81
= 324 km

Distance between Town B and Town C
= 324 + 243
= 567 km

Since Brandon passed the grocery store at the same time as Howard, it means that Brandon travelled 324 km in 2 hours.

Brandon's speed during the journey
= 324 ÷ 2
= 162 km/h

Duration that Brandon took to reach Town C after passing the grocery store
= 243 ÷ 162
= 1.5 h

Duration that Howard took to reach Town C after passing the grocery store
= 243 ÷ 81
= 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

Brandon reached Town C 90 minutes earlier than Howard.

Answer(s): 90 min