Tim started driving from Town G towards Town H at 15 30 at an average speed of 60 km/h. Ahmad began driving from Town G towards Town H at 18 20 at an average speed of 110 km/h.
- At what time did Ahmad pass Tim on the road?
- 1110 hours after passing Tim, Ahmad reached Town H. At what time did Tim reach Town H?
(a)
From 15 30 to 18 20 = 2 h 50 min
Time that Tim travelled before Ahmad started driving = 2 h 50 min
1 h = 60 min
2 h 50 min = 2
5060 h = 2
56 h
Distance that Tim travelled before Ahmad started driving
= 2
56 x 60
=
176 x 60
= 170 km
Difference between Ahmad's and Tim's speed
= 110 - 60
= 50 km/h
Time that Ahmad took to catch up with Tim
= 170 ÷ 50
= 3.4 h
= 3 h 24 min
3 h 24 min after 18 20 = 21 44
Time that Ahmad passed Tim on the road = 21 44
(b)
1
110 h = 1 h 6 min
Total time that Ahmad travelled
= 1 h 6 min + 3 h 24 min
= 4 h 30 min
4 h 30 min = 4
3060h = 4
12h
Distance between Town G and Town H
= 4
12 x 110
= 495 km
Time that Tim travelled from Town G to Town H
= 495 ÷ 60
= 8.25 h
= 8 h 15 min
8 h 15 min after 15 30 = 23 45
Time that Tim reached Town H = 23 45
Answer: (a) 21 44; (b) 23 45