At 7 a.m., Ian started from City M and travelled towards City N and his speed remained constant throughout. At 10 a.m., Wendy started her journey from City M towards City N at an average speed of 84 km/h. Wendy overtook Ian at 1 p.m. After overtaking, Wendy carried on her journey at the same average speed and reached at City N at 3:45 p.m.

1. Find Ian'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 Wendy had travelled until Wendy overtook Ian
= 3 x 84
= 252 km

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

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

(b)
From 10 a.m. to 3:45 p.m. = 5 h 45 min

1 h = 60 min
5 h 45 min = 5 ⁴⁵ ₆₀
 h = 5 ³₄ h

Distance between the two cities
= 5 ³₄ x 84
= ²³₄ x 84
= 483 km

Answer(s): (a) 42 km/h; (b) 483 km