At 9 a.m., Ken started from City L and travelled towards City M and his speed remained constant throughout. At 10 a.m., Wendy started her journey from City L towards City M at an average speed of 84 km/h. Wendy overtook Ken at 3 p.m. After overtaking, Wendy carried on her journey at the same average speed and reached at City M at 4:15 p.m.

1. Find Ken'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 Wendy had travelled until Wendy overtook Ken
= 5 x 84
= 420 km

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

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

(b)
From 10 a.m. to 4:15 p.m. = 6 h 15 min

1 h = 60 min
6 h 15 min = 6 ¹⁵ ₆₀
 h = 6 ¹₄ h

Distance between the two cities
= 6 ¹₄ x 84
= ²⁵₄ x 84
= 525 km

Answer(s): (a) 70 km/h; (b) 525 km