At 8 a.m., Ivan started from City L and travelled towards City M and his speed remained constant throughout. At 9 a.m., Winnie started her journey from City L towards City M at an average speed of 90 km/h. Winnie overtook Ivan at 2 p.m. After overtaking, Winnie carried on her journey at the same average speed and reached at City M at 4:30 p.m.
- Find Ivan's average speed in km/h.
- What is the distance between the two cities?
(a)
From 9 a.m. to 2 p.m. = 5 h
Distance that Winnie had travelled until Winnie overtook Ivan
= 5 x 90
= 450 km
From 8 a.m. to 2 p.m. = 6 h
Ivan's average speed
= 450 ÷ 6
= 75 km/h
(b)
From 9 a.m. to 4:30 p.m. = 7 h 30 min
1 h = 60 min
7 h 30 min = 7
30 60
h = 7
12 h
Distance between the two cities
= 7
12 x 90
=
152 x 90
= 675 km
Answer(s): (a) 75 km/h; (b) 675 km