At 9 a.m., Fred started from City J and travelled towards City K and his speed remained constant throughout. At 10 a.m., Esther started her journey from City J towards City K at an average speed of 84 km/h. Esther overtook Fred at 1 p.m. After overtaking, Esther carried on her journey at the same average speed and reached at City K at 5:30 p.m.

1. Find Fred'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 Esther had travelled until Esther overtook Fred
= 3 x 84
= 252 km

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

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

(b)
From 10 a.m. to 5:30 p.m. = 7 h 30 min

1 h = 60 min
7 h 30 min = 7 ³⁰ ₆₀
 h = 7 ¹₂ h

Distance between the two cities
= 7 ¹₂ x 84
= ¹⁵₂ x 84
= 630 km

Answer(s): (a) 63 km/h; (b) 630 km