Zeph started driving from Town Q towards Town R at 14 30 at an average speed of 60 km/h. Sam began driving from Town Q towards Town R at 17 20 at an average speed of 110 km/h.
- At what time did Sam pass Zeph on the road?
- 1110 hours after passing Zeph, Sam reached Town R. At what time did Zeph reach Town R?
(a)
From 14 30 to 17 20 = 2 h 50 min
Time that Zeph travelled before Sam started driving = 2 h 50 min
1 h = 60 min
2 h 50 min = 2
5060 h = 2
56 h
Distance that Zeph travelled before Sam started driving
= 2
56 x 60
=
176 x 60
= 170 km
Difference between Sam's and Zeph's speed
= 110 - 60
= 50 km/h
Time that Sam took to catch up with Zeph
= 170 ÷ 50
= 3.4 h
= 3 h 24 min
3 h 24 min after 17 20 = 20 44
Time that Sam passed Zeph on the road = 20 44
(b)
1
110 h = 1 h 6 min
Total time that Sam travelled
= 1 h 6 min + 3 h 24 min
= 4 h 30 min
4 h 30 min = 4
3060h = 4
12h
Distance between Town Q and Town R
= 4
12 x 110
= 495 km
Time that Zeph travelled from Town Q to Town R
= 495 ÷ 60
= 8.25 h
= 8 h 15 min
8 h 15 min after 14 30 = 22 45
Time that Zeph reached Town R = 22 45
Answer: (a) 20 44; (b) 22 45