At 7 a.m., Oscar started from City V and travelled towards City W and his speed remained constant throughout. At 10 a.m., Tiffany started her journey from City V towards City W at an average speed of 78 km/h. Tiffany overtook Oscar at 1 p.m. After overtaking, Tiffany carried on her journey at the same average speed and reached at City W at 6:50 p.m.
- Find Oscar'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 Tiffany had travelled until Tiffany overtook Oscar
= 3 x 78
= 234 km
From 7 a.m. to 1 p.m. = 6 h
Oscar's average speed
= 234 ÷ 6
= 39 km/h
(b)
From 10 a.m. to 6:50 p.m. = 8 h 50 min
1 h = 60 min
8 h 50 min = 8
50 60
h = 8
56 h
Distance between the two cities
= 8
56 x 78
=
536 x 78
= 689 km
Answer(s): (a) 39 km/h; (b) 689 km