At 8 a.m., Brandon started from City L and travelled towards City M and his speed remained constant throughout. At 10 a.m., Gwen started her journey from City L towards City M at an average speed of 90 km/h. Gwen overtook Brandon at 2 p.m. After overtaking, Gwen carried on her journey at the same average speed and reached at City M at 4:30 p.m.
- Find Brandon'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 Gwen had travelled until Gwen overtook Brandon
= 4 x 90
= 360 km
From 8 a.m. to 2 p.m. = 6 h
Brandon's average speed
= 360 ÷ 6
= 60 km/h
(b)
From 10 a.m. to 4:30 p.m. = 6 h 30 min
1 h = 60 min
6 h 30 min = 6
30 60
h = 6
12 h
Distance between the two cities
= 6
12 x 90
=
132 x 90
= 585 km
Answer(s): (a) 60 km/h; (b) 585 km