At 8 a.m., Tommy started from City W and travelled towards City X and his speed remained constant throughout. At 10 a.m., Diana started her journey from City W towards City X at an average speed of 84 km/h. Diana overtook Tommy at 2 p.m. After overtaking, Diana carried on her journey at the same average speed and reached at City X at 4:20 p.m.
- Find Tommy's average speed in km/h.
- 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 Tommy
= 4 x 84
= 336 km
From 8 a.m. to 2 p.m. = 6 h
Tommy's average speed
= 336 ÷ 6
= 56 km/h
(b)
From 10 a.m. to 4:20 p.m. = 6 h 20 min
1 h = 60 min
6 h 20 min = 6
20 60
h = 6
13 h
Distance between the two cities
= 6
13 x 84
=
193 x 84
= 532 km
Answer(s): (a) 56 km/h; (b) 532 km