At 9 a.m., Tommy started from City J and travelled towards City K and his speed remained constant throughout. At 10 a.m., Kylie started her journey from City J towards City K at an average speed of 90 km/h. Kylie overtook Tommy at 3 p.m. After overtaking, Kylie carried on her journey at the same average speed and reached at City K at 3:30 p.m.

1. Find Tommy'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 Kylie had travelled until Kylie overtook Tommy
= 5 x 90
= 450 km

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

Tommy's average speed
= 450 ÷ 6
= 75 km/h

(b)
From 10 a.m. to 3:30 p.m. = 5 h 30 min

1 h = 60 min
5 h 30 min = 5 ³⁰ ₆₀
 h = 5 ¹₂ h

Distance between the two cities
= 5 ¹₂ x 90
= ¹¹₂ x 90
= 495 km

Answer(s): (a) 75 km/h; (b) 495 km