At 7 a.m., Charlie started from City W and travelled towards City X and his speed remained constant throughout. At 8 a.m., Shannon started her journey from City W towards City X at an average speed of 72 km/h. Shannon overtook Charlie at 1 p.m. After overtaking, Shannon carried on her journey at the same average speed and reached at City X at 5:35 p.m.
- Find Charlie's average speed in km/h.
- What is the distance between the two cities?
(a)
From 8 a.m. to 1 p.m. = 5 h
Distance that Shannon had travelled until Shannon overtook Charlie
= 5 x 72
= 360 km
From 7 a.m. to 1 p.m. = 6 h
Charlie's average speed
= 360 ÷ 6
= 60 km/h
(b)
From 8 a.m. to 5:35 p.m. = 9 h 35 min
1 h = 60 min
9 h 35 min = 9
35 60
h = 9
712 h
Distance between the two cities
= 9
712 x 72
=
11512 x 72
= 690 km
Answer(s): (a) 60 km/h; (b) 690 km