At 9 a.m., Oliver started from City P and travelled towards City Q and his speed remained constant throughout. At 10 a.m., Cindy started her journey from City P towards City Q at an average speed of 72 km/h. Cindy overtook Oliver at 1 p.m. After overtaking, Cindy carried on her journey at the same average speed and reached at City Q at 3:45 p.m.
- Find Oliver'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 Cindy had travelled until Cindy overtook Oliver
= 3 x 72
= 216 km
From 9 a.m. to 1 p.m. = 4 h
Oliver's average speed
= 216 ÷ 4
= 54 km/h
(b)
From 10 a.m. to 3:45 p.m. = 5 h 45 min
1 h = 60 min
5 h 45 min = 5
45 60
h = 5
34 h
Distance between the two cities
= 5
34 x 72
=
234 x 72
= 414 km
Answer(s): (a) 54 km/h; (b) 414 km