At 9 a.m., Andy started from City Z and travelled towards City A and his speed remained constant throughout. At 10 a.m., Tina started her journey from City Z towards City A at an average speed of 84 km/h. Tina overtook Andy at 3 p.m. After overtaking, Tina carried on her journey at the same average speed and reached at City A at 5:25 p.m.

1. Find Andy'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 Tina had travelled until Tina overtook Andy
= 5 x 84
= 420 km

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

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

(b)
From 10 a.m. to 5:25 p.m. = 7 h 25 min

1 h = 60 min
7 h 25 min = 7 ²⁵ ₆₀
 h = 7 ⁵₁₂ h

Distance between the two cities
= 7 ⁵₁₂ x 84
= ⁸⁹₁₂ x 84
= 623 km

Answer(s): (a) 70 km/h; (b) 623 km