At 9 a.m., Sam started from City H and travelled towards City J and his speed remained constant throughout. At 10 a.m., Tina started her journey from City H towards City J at an average speed of 84 km/h. Tina overtook Sam at 3 p.m. After overtaking, Tina carried on her journey at the same average speed and reached at City J at 2:45 p.m.

1. Find Sam'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 Sam
= 5 x 84
= 420 km

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

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

(b)
From 10 a.m. to 2:45 p.m. = 4 h 45 min

1 h = 60 min
4 h 45 min = 4 ⁴⁵ ₆₀
 h = 4 ³₄ h

Distance between the two cities
= 4 ³₄ x 84
= ¹⁹₄ x 84
= 399 km

Answer(s): (a) 70 km/h; (b) 399 km