At 8 a.m., Paul started from City R and travelled towards City S and his speed remained constant throughout. At 9 a.m., Fiona started her journey from City R towards City S at an average speed of 90 km/h. Fiona overtook Paul at 2 p.m. After overtaking, Fiona carried on her journey at the same average speed and reached at City S at 4:30 p.m.

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

(a)
From 9 a.m. to 2 p.m. = 5 h

Distance that Fiona had travelled until Fiona overtook Paul
= 5 x 90
= 450 km

From 8 a.m. to 2 p.m. = 6 h

Paul's average speed
= 450 ÷ 6
= 75 km/h

(b)
From 9 a.m. to 4:30 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 90
= ¹⁵₂ x 90
= 675 km

Answer(s): (a) 75 km/h; (b) 675 km