At 7 a.m., Oscar started from City F and travelled towards City G and his speed remained constant throughout. At 8 a.m., Xandra started her journey from City F towards City G at an average speed of 84 km/h. Xandra overtook Oscar at 1 p.m. After overtaking, Xandra carried on her journey at the same average speed and reached at City G at 6:20 p.m.

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

(a)
From 8 a.m. to 1 p.m. = 5 h

Distance that Xandra had travelled until Xandra overtook Oscar
= 5 x 84
= 420 km

From 7 a.m. to 1 p.m. = 6 h

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

(b)
From 8 a.m. to 6:20 p.m. = 10 h 20 min

1 h = 60 min
10 h 20 min = 10 ²⁰ ₆₀
 h = 10 ¹₃ h

Distance between the two cities
= 10 ¹₃ x 84
= ³¹₃ x 84
= 868 km

Answer(s): (a) 70 km/h; (b) 868 km