At 8 a.m., Ahmad started from City B and travelled towards City C and his speed remained constant throughout. At 9 a.m., Yen started her journey from City B towards City C at an average speed of 90 km/h. Yen overtook Ahmad at 2 p.m. After overtaking, Yen carried on her journey at the same average speed and reached at City C at 4:40 p.m.
- Find Ahmad'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 Yen had travelled until Yen overtook Ahmad
= 5 x 90
= 450 km
From 8 a.m. to 2 p.m. = 6 h
Ahmad's average speed
= 450 ÷ 6
= 75 km/h
(b)
From 9 a.m. to 4:40 p.m. = 7 h 40 min
1 h = 60 min
7 h 40 min = 7
40 60
h = 7
23 h
Distance between the two cities
= 7
23 x 90
=
233 x 90
= 690 km
Answer(s): (a) 75 km/h; (b) 690 km