At 9 a.m., Henry started from City W and travelled towards City X and his speed remained constant throughout. At 10 a.m., Xandra started her journey from City W towards City X at an average speed of 72 km/h. Xandra overtook Henry at 3 p.m. After overtaking, Xandra carried on her journey at the same average speed and reached at City X at 2:20 p.m.
- Find Henry's average speed in km/h.
- What is the distance between the two cities?
(a)
From 10 a.m. to 3 p.m. = 5 h
Distance that Xandra had travelled until Xandra overtook Henry
= 5 x 72
= 360 km
From 9 a.m. to 3 p.m. = 6 h
Henry's average speed
= 360 ÷ 6
= 60 km/h
(b)
From 10 a.m. to 2:20 p.m. = 4 h 20 min
1 h = 60 min
4 h 20 min = 4
20 60
h = 4
13 h
Distance between the two cities
= 4
13 x 72
=
133 x 72
= 312 km
Answer(s): (a) 60 km/h; (b) 312 km