At 7 a.m., Ethan started from City B and travelled towards City C and his speed remained constant throughout. At 9 a.m., Zoe started her journey from City B towards City C at an average speed of 87 km/h. Zoe overtook Ethan at 1 p.m. After overtaking, Zoe carried on her journey at the same average speed and reached at City C at 3:20 p.m.

1. Find Ethan'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 Zoe had travelled until Zoe overtook Ethan
= 4 x 87
= 348 km

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

Ethan's average speed
= 348 ÷ 6
= 58 km/h

(b)
From 9 a.m. to 3:20 p.m. = 6 h 20 min

1 h = 60 min
6 h 20 min = 6 ²⁰ ₆₀
 h = 6 ¹₃ h

Distance between the two cities
= 6 ¹₃ x 87
= ¹⁹₃ x 87
= 551 km

Answer(s): (a) 58 km/h; (b) 551 km