At 8 a.m., Gabriel started from City B and travelled towards City C and his speed remained constant throughout. At 9 a.m., Tina started her journey from City B towards City C at an average speed of 72 km/h. Tina overtook Gabriel at 2 p.m. After overtaking, Tina carried on her journey at the same average speed and reached at City C at 3:25 p.m.

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

(a)
From 9 a.m. to 2 p.m. = 5 h

Distance that Tina had travelled until Tina overtook Gabriel
= 5 x 72
= 360 km

From 8 a.m. to 2 p.m. = 6 h

Gabriel's average speed
= 360 ÷ 6
= 60 km/h

(b)
From 9 a.m. to 3:25 p.m. = 6 h 25 min

1 h = 60 min
6 h 25 min = 6 ²⁵ ₆₀
 h = 6 ⁵₁₂ h

Distance between the two cities
= 6 ⁵₁₂ x 72
= ⁷⁷₁₂ x 72
= 462 km

Answer(s): (a) 60 km/h; (b) 462 km