At 9 a.m., Asher started from City A and travelled towards City B and his speed remained constant throughout. At 10 a.m., Kathy started her journey from City A towards City B at an average speed of 68 km/h. Kathy overtook Asher at 1 p.m. After overtaking, Kathy carried on her journey at the same average speed and reached at City B at 6:30 p.m.
- Find Asher's average speed in km/h.
- What is the distance between the two cities?
(a)
From 10 a.m. to 1 p.m. = 3 h
Distance that Kathy had travelled until Kathy overtook Asher
= 3 x 68
= 204 km
From 9 a.m. to 1 p.m. = 4 h
Asher's average speed
= 204 ÷ 4
= 51 km/h
(b)
From 10 a.m. to 6:30 p.m. = 8 h 30 min
1 h = 60 min
8 h 30 min = 8
30 60
h = 8
12 h
Distance between the two cities
= 8
12 x 68
=
172 x 68
= 578 km
Answer(s): (a) 51 km/h; (b) 578 km