At 9 a.m., Vaidev started from City Z and travelled towards City A and his speed remained constant throughout. At 10 a.m., Yoko started her journey from City Z towards City A at an average speed of 72 km/h. Yoko overtook Vaidev at 3 p.m. After overtaking, Yoko carried on her journey at the same average speed and reached at City A at 6:35 p.m.
- Find Vaidev's average speed in km/h.
- What is the distance between the two cities?
(a)
From 10 a.m. to 3 p.m. = 5 h
Distance that Yoko had travelled until Yoko overtook Vaidev
= 5 x 72
= 360 km
From 9 a.m. to 3 p.m. = 6 h
Vaidev's average speed
= 360 ÷ 6
= 60 km/h
(b)
From 10 a.m. to 6:35 p.m. = 8 h 35 min
1 h = 60 min
8 h 35 min = 8
35 60
h = 8
712 h
Distance between the two cities
= 8
712 x 72
=
10312 x 72
= 618 km
Answer(s): (a) 60 km/h; (b) 618 km