At 8 a.m., Seth started from City F and travelled towards City G and his speed remained constant throughout. At 10 a.m., Opal started her journey from City F towards City G at an average speed of 84 km/h. Opal overtook Seth at 2 p.m. After overtaking, Opal carried on her journey at the same average speed and reached at City G at 5:30 p.m.
- Find Seth's average speed in km/h.
- What is the distance between the two cities?
(a)
From 10 a.m. to 2 p.m. = 4 h
Distance that Opal had travelled until Opal overtook Seth
= 4 x 84
= 336 km
From 8 a.m. to 2 p.m. = 6 h
Seth's average speed
= 336 ÷ 6
= 56 km/h
(b)
From 10 a.m. to 5:30 p.m. = 7 h 30 min
1 h = 60 min
7 h 30 min = 7
30 60
h = 7
12 h
Distance between the two cities
= 7
12 x 84
=
152 x 84
= 630 km
Answer(s): (a) 56 km/h; (b) 630 km