At 7 a.m., Jeremy started from City R and travelled towards City S and his speed remained constant throughout. At 10 a.m., Opal started her journey from City R towards City S at an average speed of 90 km/h. Opal overtook Jeremy at 1 p.m. After overtaking, Opal carried on her journey at the same average speed and reached at City S at 3:20 p.m.

1. Find Jeremy'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 Opal had travelled until Opal overtook Jeremy
= 3 x 90
= 270 km

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

Jeremy's average speed
= 270 ÷ 6
= 45 km/h

(b)
From 10 a.m. to 3:20 p.m. = 5 h 20 min

1 h = 60 min
5 h 20 min = 5 ²⁰ ₆₀
 h = 5 ¹₃ h

Distance between the two cities
= 5 ¹₃ x 90
= ¹⁶₃ x 90
= 480 km

Answer(s): (a) 45 km/h; (b) 480 km