At 8 a.m., Tom started from City S and travelled towards City T and his speed remained constant throughout. At 9 a.m., Sarah started her journey from City S towards City T at an average speed of 72 km/h. Sarah overtook Tom at 2 p.m. After overtaking, Sarah carried on her journey at the same average speed and reached at City T at 6:45 p.m.

1. Find Tom'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 Sarah had travelled until Sarah overtook Tom
= 5 x 72
= 360 km

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

Tom's average speed
= 360 ÷ 6
= 60 km/h

(b)
From 9 a.m. to 6:45 p.m. = 9 h 45 min

1 h = 60 min
9 h 45 min = 9 ⁴⁵ ₆₀
 h = 9 ³₄ h

Distance between the two cities
= 9 ³₄ x 72
= ³⁹₄ x 72
= 702 km

Answer(s): (a) 60 km/h; (b) 702 km