At 11 40, Justin left Town Y for Town Z, driving at a speed of 76 km/h. At 14 40, Jeremy also left Town Y for Town Z driving at a certain speed. Both of them did not change their speed throughout the journey. At 17 40, both of them passed a museum that was 228 km away from Town Z. How many minutes earlier did Jeremy reach Town Z than Justin?

Distance that Justin travelled
= 6 x 76
= 456 km

Distance between Town Y and Town Z
= 456 + 228
= 684 km

Since Jeremy passed the museum at the same time as Justin, it means that Jeremy travelled 456 km in 3 hours.

Jeremy's speed during the journey
= 456 ÷ 3
= 152 km/h

Duration that Jeremy took to reach Town Z after passing the museum
= 228 ÷ 152
= 1.5 h

Duration that Justin took to reach Town Z after passing the museum
= 228 ÷ 76
= 3 h

Difference between the time they took to reach Town Z
= 3 - 1.5
= 1.5 h

1 h = 60 min
1.5 h = 1.5 x 60 = 90 min

Jeremy reached Town Z 90 minutes earlier than Justin.

Answer(s): 90 min