At 9 a.m., Sam started from City V and travelled towards City W and his speed remained constant throughout. At 10 a.m., Shannon started her journey from City V towards City W at an average speed of 84 km/h. Shannon overtook Sam at 1 p.m. After overtaking, Shannon carried on her journey at the same average speed and reached at City W at 6:45 p.m.
- Find Sam's average speed in km/h.
- What is the distance between the two cities?
(a)
From 10 a.m. to 1 p.m. = 3 h
Distance that Shannon had travelled until Shannon overtook Sam
= 3 x 84
= 252 km
From 9 a.m. to 1 p.m. = 4 h
Sam's average speed
= 252 ÷ 4
= 63 km/h
(b)
From 10 a.m. to 6:45 p.m. = 8 h 45 min
1 h = 60 min
8 h 45 min = 8
45 60
h = 8
34 h
Distance between the two cities
= 8
34 x 84
=
354 x 84
= 735 km
Answer(s): (a) 63 km/h; (b) 735 km