At 7 a.m., Dylan started from City Q and travelled towards City R and his speed remained constant throughout. At 9 a.m., Marion started her journey from City Q towards City R at an average speed of 84 km/h. Marion overtook Dylan at 1 p.m. After overtaking, Marion carried on her journey at the same average speed and reached at City R at 6:15 p.m.

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

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

Distance that Marion had travelled until Marion overtook Dylan
= 4 x 84
= 336 km

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

Dylan's average speed
= 336 ÷ 6
= 56 km/h

(b)
From 9 a.m. to 6:15 p.m. = 9 h 15 min

1 h = 60 min
9 h 15 min = 9 ¹⁵ ₆₀
 h = 9 ¹₄ h

Distance between the two cities
= 9 ¹₄ x 84
= ³⁷₄ x 84
= 777 km

Answer(s): (a) 56 km/h; (b) 777 km