At 9 a.m., Simon started from City Y and travelled towards City Z and his speed remained constant throughout. At 10 a.m., Sabrina started her journey from City Y towards City Z at an average speed of 84 km/h. Sabrina overtook Simon at 1 p.m. After overtaking, Sabrina carried on her journey at the same average speed and reached at City Z at 6:25 p.m.

1. Find Simon'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 Sabrina had travelled until Sabrina overtook Simon
= 3 x 84
= 252 km

From 9 a.m. to 1 p.m. = 4 h

Simon's average speed
= 252 ÷ 4
= 63 km/h

(b)
From 10 a.m. to 6:25 p.m. = 8 h 25 min

1 h = 60 min
8 h 25 min = 8 ²⁵ ₆₀
 h = 8 ⁵₁₂ h

Distance between the two cities
= 8 ⁵₁₂ x 84
= ¹⁰¹₁₂ x 84
= 707 km

Answer(s): (a) 63 km/h; (b) 707 km