At 7 a.m., Sean started from City T and travelled towards City U and his speed remained constant throughout. At 10 a.m., Eva started her journey from City T towards City U at an average speed of 72 km/h. Eva overtook Sean at 1 p.m. After overtaking, Eva carried on her journey at the same average speed and reached at City U at 5:50 p.m.
- Find Sean'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 Eva had travelled until Eva overtook Sean
= 3 x 72
= 216 km
From 7 a.m. to 1 p.m. = 6 h
Sean's average speed
= 216 ÷ 6
= 36 km/h
(b)
From 10 a.m. to 5:50 p.m. = 7 h 50 min
1 h = 60 min
7 h 50 min = 7
50 60
h = 7
56 h
Distance between the two cities
= 7
56 x 72
=
476 x 72
= 564 km
Answer(s): (a) 36 km/h; (b) 564 km