At 7 a.m., Ben started from City S and travelled towards City T and his speed remained constant throughout. At 8 a.m., Sabrina started her journey from City S towards City T at an average speed of 84 km/h. Sabrina overtook Ben at 1 p.m. After overtaking, Sabrina carried on her journey at the same average speed and reached at City T at 4:15 p.m.
- Find Ben'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 Sabrina had travelled until Sabrina overtook Ben
= 5 x 84
= 420 km
From 7 a.m. to 1 p.m. = 6 h
Ben's average speed
= 420 ÷ 6
= 70 km/h
(b)
From 8 a.m. to 4:15 p.m. = 8 h 15 min
1 h = 60 min
8 h 15 min = 8
15 60
h = 8
14 h
Distance between the two cities
= 8
14 x 84
=
334 x 84
= 693 km
Answer(s): (a) 70 km/h; (b) 693 km