At 9 a.m., Justin started from City K and travelled towards City L and his speed remained constant throughout. At 10 a.m., Tina started her journey from City K towards City L at an average speed of 88 km/h. Tina overtook Justin at 1 p.m. After overtaking, Tina carried on her journey at the same average speed and reached at City L at 4:30 p.m.

1. Find Justin'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 Tina had travelled until Tina overtook Justin
= 3 x 88
= 264 km

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

Justin's average speed
= 264 ÷ 4
= 66 km/h

(b)
From 10 a.m. to 4:30 p.m. = 6 h 30 min

1 h = 60 min
6 h 30 min = 6 ³⁰ ₆₀
 h = 6 ¹₂ h

Distance between the two cities
= 6 ¹₂ x 88
= ¹³₂ x 88
= 572 km

Answer(s): (a) 66 km/h; (b) 572 km