At 7 a.m., Seth started from City E and travelled towards City F and his speed remained constant throughout. At 10 a.m., Joelle started her journey from City E towards City F at an average speed of 72 km/h. Joelle overtook Seth at 1 p.m. After overtaking, Joelle carried on her journey at the same average speed and reached at City F at 5:40 p.m.
- Find Seth'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 Joelle had travelled until Joelle overtook Seth
= 3 x 72
= 216 km
From 7 a.m. to 1 p.m. = 6 h
Seth's average speed
= 216 ÷ 6
= 36 km/h
(b)
From 10 a.m. to 5:40 p.m. = 7 h 40 min
1 h = 60 min
7 h 40 min = 7
40 60
h = 7
23 h
Distance between the two cities
= 7
23 x 72
=
233 x 72
= 552 km
Answer(s): (a) 36 km/h; (b) 552 km