At 9 a.m., Wesley started from City C and travelled towards City D and his speed remained constant throughout. At 10 a.m., Roshel started her journey from City C towards City D at an average speed of 80 km/h. Roshel overtook Wesley at 1 p.m. After overtaking, Roshel carried on her journey at the same average speed and reached at City D at 3:15 p.m.

1. Find Wesley's average speed in km/h.
2. What is the distance between the two cities?

(a)
From 10 a.m. to 1 p.m. = 3 h

Distance that Roshel had travelled until Roshel overtook Wesley
= 3 x 80
= 240 km

From 9 a.m. to 1 p.m. = 4 h

Wesley's average speed
= 240 ÷ 4
= 60 km/h

(b)
From 10 a.m. to 3:15 p.m. = 5 h 15 min

1 h = 60 min
5 h 15 min = 5 ¹⁵ ₆₀
 h = 5 ¹₄ h

Distance between the two cities
= 5 ¹₄ x 80
= ²¹₄ x 80
= 420 km

Answer(s): (a) 60 km/h; (b) 420 km