At 7 a.m., John started from City F and travelled towards City G and his speed remained constant throughout. At 8 a.m., Zara started her journey from City F towards City G at an average speed of 66 km/h. Zara overtook John at 1 p.m. After overtaking, Zara carried on her journey at the same average speed and reached at City G at 1:40 p.m.
- Find John'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 Zara had travelled until Zara overtook John
= 5 x 66
= 330 km
From 7 a.m. to 1 p.m. = 6 h
John's average speed
= 330 ÷ 6
= 55 km/h
(b)
From 8 a.m. to 1:40 p.m. = 5 h 40 min
1 h = 60 min
5 h 40 min = 5
40 60
h = 5
23 h
Distance between the two cities
= 5
23 x 66
=
173 x 66
= 374 km
Answer(s): (a) 55 km/h; (b) 374 km