At 8 a.m., Vincent started from City C and travelled towards City D and his speed remained constant throughout. At 10 a.m., Min started her journey from City C towards City D at an average speed of 72 km/h. Min overtook Vincent at 2 p.m. After overtaking, Min carried on her journey at the same average speed and reached at City D at 3:35 p.m.
- Find Vincent'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 Min had travelled until Min overtook Vincent
= 4 x 72
= 288 km
From 8 a.m. to 2 p.m. = 6 h
Vincent's average speed
= 288 ÷ 6
= 48 km/h
(b)
From 10 a.m. to 3:35 p.m. = 5 h 35 min
1 h = 60 min
5 h 35 min = 5
35 60
h = 5
712 h
Distance between the two cities
= 5
712 x 72
=
6712 x 72
= 402 km
Answer(s): (a) 48 km/h; (b) 402 km