At 8 a.m., Cole started from City C and travelled towards City D and his speed remained constant throughout. At 10 a.m., Diana started her journey from City C towards City D at an average speed of 84 km/h. Diana overtook Cole at 2 p.m. After overtaking, Diana carried on her journey at the same average speed and reached at City D at 1:40 p.m.

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

(a)
From 10 a.m. to 2 p.m. = 4 h

Distance that Diana had travelled until Diana overtook Cole
= 4 x 84
= 336 km

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

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

(b)
From 10 a.m. to 1:40 p.m. = 3 h 40 min

1 h = 60 min
3 h 40 min = 3 ⁴⁰ ₆₀
 h = 3 ²₃ h

Distance between the two cities
= 3 ²₃ x 84
= ¹¹₃ x 84
= 308 km

Answer(s): (a) 56 km/h; (b) 308 km