At 7 a.m., Ethan started from City R and travelled towards City S and his speed remained constant throughout. At 9 a.m., Winnie started her journey from City R towards City S at an average speed of 75 km/h. Winnie overtook Ethan at 1 p.m. After overtaking, Winnie carried on her journey at the same average speed and reached at City S at 6:40 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 Winnie had travelled until Winnie overtook Ethan
= 4 x 75
= 300 km

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

Ethan's average speed
= 300 ÷ 6
= 50 km/h

(b)
From 9 a.m. to 6:40 p.m. = 9 h 40 min

1 h = 60 min
9 h 40 min = 9 ⁴⁰ ₆₀
 h = 9 ²₃ h

Distance between the two cities
= 9 ²₃ x 75
= ²⁹₃ x 75
= 725 km

Answer(s): (a) 50 km/h; (b) 725 km