At 10 20, Andy left Town Q for Town R, driving at a speed of 66 km/h. At 13 20, Tim also left Town Q for Town R driving at a certain speed. Both of them did not change their speed throughout the journey. At 16 20, both of them passed a school that was 198 km away from Town R. How many minutes earlier did Tim reach Town R than Andy?
Duration that Andy travelled from 10 20 to 16 20 = 6 h
Distance that Andy travelled
= 6 x 66
= 396 km
Distance between Town Q and Town R
= 396 + 198
= 594 km
Since Tim passed the school at the same time as Andy, it means that Tim travelled 396 km in 3 hours.
Tim's speed during the journey
= 396 ÷ 3
= 132 km/h
Duration that Tim took to reach Town R after passing the school
= 198 ÷ 132
= 1.5 h
Duration that Andy took to reach Town R after passing the school
= 198 ÷ 66
= 3 h
Difference between the time they took to reach Town R
= 3 - 1.5
= 1.5 h
1 h = 60 min
1.5 h = 1.5 x 60 = 90 min
Tim reached Town R 90 minutes earlier than Andy.
Answer(s): 90 min
