At 9 a.m., Ethan started from City V and travelled towards City W and his speed remained constant throughout. At 10 a.m., Risa started her journey from City V towards City W at an average speed of 66 km/h. Risa overtook Ethan at 3 p.m. After overtaking, Risa carried on her journey at the same average speed and reached at City W at 1:50 p.m.

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

(a)
From 10 a.m. to 3 p.m. = 5 h

Distance that Risa had travelled until Risa overtook Ethan
= 5 x 66
= 330 km

From 9 a.m. to 3 p.m. = 6 h

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

(b)
From 10 a.m. to 1:50 p.m. = 3 h 50 min

1 h = 60 min
3 h 50 min = 3 ⁵⁰ ₆₀
 h = 3 ⁵₆ h

Distance between the two cities
= 3 ⁵₆ x 66
= ²³₆ x 66
= 253 km

Answer(s): (a) 55 km/h; (b) 253 km