At 7 a.m., Sam started from City B and travelled towards City C and his speed remained constant throughout. At 9 a.m., Linda started her journey from City B towards City C at an average speed of 84 km/h. Linda overtook Sam at 1 p.m. After overtaking, Linda carried on her journey at the same average speed and reached at City C at 4:40 p.m.

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

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

Distance that Linda had travelled until Linda overtook Sam
= 4 x 84
= 336 km

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

Sam's average speed
= 336 ÷ 6
= 56 km/h

(b)
From 9 a.m. to 4:40 p.m. = 7 h 40 min

1 h = 60 min
7 h 40 min = 7 ⁴⁰ ₆₀
 h = 7 ²₃ h

Distance between the two cities
= 7 ²₃ x 84
= ²³₃ x 84
= 644 km

Answer(s): (a) 56 km/h; (b) 644 km