At 7 a.m., John started from City V and travelled towards City W and his speed remained constant throughout. At 8 a.m., Diana started her journey from City V towards City W at an average speed of 84 km/h. Diana overtook John at 1 p.m. After overtaking, Diana carried on her journey at the same average speed and reached at City W at 6:40 p.m.

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

(a)
From 8 a.m. to 1 p.m. = 5 h

Distance that Diana had travelled until Diana overtook John
= 5 x 84
= 420 km

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

John's average speed
= 420 ÷ 6
= 70 km/h

(b)
From 8 a.m. to 6:40 p.m. = 10 h 40 min

1 h = 60 min
10 h 40 min = 10 ⁴⁰ ₆₀
 h = 10 ²₃ h

Distance between the two cities
= 10 ²₃ x 84
= ³²₃ x 84
= 896 km

Answer(s): (a) 70 km/h; (b) 896 km