At 8 a.m., George started from City B and travelled towards City C and his speed remained constant throughout. At 10 a.m., Joelle started her journey from City B towards City C at an average speed of 90 km/h. Joelle overtook George at 2 p.m. After overtaking, Joelle carried on her journey at the same average speed and reached at City C at 2:20 p.m.
- Find George's average speed in km/h.
- What is the distance between the two cities?
(a)
From 10 a.m. to 2 p.m. = 4 h
Distance that Joelle had travelled until Joelle overtook George
= 4 x 90
= 360 km
From 8 a.m. to 2 p.m. = 6 h
George's average speed
= 360 ÷ 6
= 60 km/h
(b)
From 10 a.m. to 2:20 p.m. = 4 h 20 min
1 h = 60 min
4 h 20 min = 4
20 60
h = 4
13 h
Distance between the two cities
= 4
13 x 90
=
133 x 90
= 390 km
Answer(s): (a) 60 km/h; (b) 390 km