At 7 a.m., Glen started from City B and travelled towards City C and his speed remained constant throughout. At 9 a.m., Usha started her journey from City B towards City C at an average speed of 84 km/h. Usha overtook Glen at 1 p.m. After overtaking, Usha carried on her journey at the same average speed and reached at City C at 5:35 p.m.

1. Find Glen'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 Usha had travelled until Usha overtook Glen
= 4 x 84
= 336 km

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

Glen's average speed
= 336 ÷ 6
= 56 km/h

(b)
From 9 a.m. to 5:35 p.m. = 8 h 35 min

1 h = 60 min
8 h 35 min = 8 ³⁵ ₆₀
 h = 8 ⁷₁₂ h

Distance between the two cities
= 8 ⁷₁₂ x 84
= ¹⁰³₁₂ x 84
= 721 km

Answer(s): (a) 56 km/h; (b) 721 km