At 7 a.m., Seth started from City A and travelled towards City B and his speed remained constant throughout. At 10 a.m., Elyse started her journey from City A towards City B at an average speed of 84 km/h. Elyse overtook Seth at 1 p.m. After overtaking, Elyse carried on her journey at the same average speed and reached at City B at 2:25 p.m.

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

(a)
From 10 a.m. to 1 p.m. = 3 h

Distance that Elyse had travelled until Elyse overtook Seth
= 3 x 84
= 252 km

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

Seth's average speed
= 252 ÷ 6
= 42 km/h

(b)
From 10 a.m. to 2:25 p.m. = 4 h 25 min

1 h = 60 min
4 h 25 min = 4 ²⁵ ₆₀
 h = 4 ⁵₁₂ h

Distance between the two cities
= 4 ⁵₁₂ x 84
= ⁵³₁₂ x 84
= 371 km

Answer(s): (a) 42 km/h; (b) 371 km