At 8 a.m., Dylan started from City E and travelled towards City F and his speed remained constant throughout. At 9 a.m., Erika started her journey from City E towards City F at an average speed of 66 km/h. Erika overtook Dylan at 2 p.m. After overtaking, Erika carried on her journey at the same average speed and reached at City F at 4:50 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 2 p.m. = 5 h

Distance that Erika had travelled until Erika overtook Dylan
= 5 x 66
= 330 km

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

Dylan's average speed
= 330 ÷ 6
= 55 km/h

(b)
From 9 a.m. to 4:50 p.m. = 7 h 50 min

1 h = 60 min
7 h 50 min = 7 ⁵⁰ ₆₀
 h = 7 ⁵₆ h

Distance between the two cities
= 7 ⁵₆ x 66
= ⁴⁷₆ x 66
= 517 km

Answer(s): (a) 55 km/h; (b) 517 km