At 9 a.m., Cole started from City K and travelled towards City L and his speed remained constant throughout. At 10 a.m., Hilda started her journey from City K towards City L at an average speed of 84 km/h. Hilda overtook Cole at 3 p.m. After overtaking, Hilda carried on her journey at the same average speed and reached at City L at 5:35 p.m.

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

(a)
From 10 a.m. to 3 p.m. = 5 h

Distance that Hilda had travelled until Hilda overtook Cole
= 5 x 84
= 420 km

From 9 a.m. to 3 p.m. = 6 h

Cole's average speed
= 420 ÷ 6
= 70 km/h

(b)
From 10 a.m. to 5:35 p.m. = 7 h 35 min

1 h = 60 min
7 h 35 min = 7 ³⁵ ₆₀
 h = 7 ⁷₁₂ h

Distance between the two cities
= 7 ⁷₁₂ x 84
= ⁹¹₁₂ x 84
= 637 km

Answer(s): (a) 70 km/h; (b) 637 km