At 8 a.m., Dylan started from City M and travelled towards City N and his speed remained constant throughout. At 10 a.m., Sarah started her journey from City M towards City N at an average speed of 66 km/h. Sarah overtook Dylan at 2 p.m. After overtaking, Sarah carried on her journey at the same average speed and reached at City N at 2:40 p.m.
- Find Dylan'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 Sarah had travelled until Sarah overtook Dylan
= 4 x 66
= 264 km
From 8 a.m. to 2 p.m. = 6 h
Dylan's average speed
= 264 ÷ 6
= 44 km/h
(b)
From 10 a.m. to 2:40 p.m. = 4 h 40 min
1 h = 60 min
4 h 40 min = 4
40 60
h = 4
23 h
Distance between the two cities
= 4
23 x 66
=
143 x 66
= 308 km
Answer(s): (a) 44 km/h; (b) 308 km