At 7 a.m., George started from City R and travelled towards City S and his speed remained constant throughout. At 9 a.m., Anna started her journey from City R towards City S at an average speed of 72 km/h. Anna overtook George at 1 p.m. After overtaking, Anna carried on her journey at the same average speed and reached at City S at 6:20 p.m.
- Find George's average speed in km/h.
- What is the distance between the two cities?
(a)
From 9 a.m. to 1 p.m. = 4 h
Distance that Anna had travelled until Anna overtook George
= 4 x 72
= 288 km
From 7 a.m. to 1 p.m. = 6 h
George's average speed
= 288 ÷ 6
= 48 km/h
(b)
From 9 a.m. to 6:20 p.m. = 9 h 20 min
1 h = 60 min
9 h 20 min = 9
20 60
h = 9
13 h
Distance between the two cities
= 9
13 x 72
=
283 x 72
= 672 km
Answer(s): (a) 48 km/h; (b) 672 km