At 7 a.m., George started from City W and travelled towards City X and his speed remained constant throughout. At 10 a.m., Rachel started her journey from City W towards City X at an average speed of 68 km/h. Rachel overtook George at 1 p.m. After overtaking, Rachel carried on her journey at the same average speed and reached at City X at 5:45 p.m.
- Find George'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 Rachel had travelled until Rachel overtook George
= 3 x 68
= 204 km
From 7 a.m. to 1 p.m. = 6 h
George's average speed
= 204 ÷ 6
= 34 km/h
(b)
From 10 a.m. to 5:45 p.m. = 7 h 45 min
1 h = 60 min
7 h 45 min = 7
45 60
h = 7
34 h
Distance between the two cities
= 7
34 x 68
=
314 x 68
= 527 km
Answer(s): (a) 34 km/h; (b) 527 km