At 8 a.m., Paul started from City A and travelled towards City B and his speed remained constant throughout. At 10 a.m., Tammy started her journey from City A towards City B at an average speed of 78 km/h. Tammy overtook Paul at 2 p.m. After overtaking, Tammy carried on her journey at the same average speed and reached at City B at 6:40 p.m.
- Find Paul'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 Tammy had travelled until Tammy overtook Paul
= 4 x 78
= 312 km
From 8 a.m. to 2 p.m. = 6 h
Paul's average speed
= 312 ÷ 6
= 52 km/h
(b)
From 10 a.m. to 6:40 p.m. = 8 h 40 min
1 h = 60 min
8 h 40 min = 8
40 60
h = 8
23 h
Distance between the two cities
= 8
23 x 78
=
263 x 78
= 676 km
Answer(s): (a) 52 km/h; (b) 676 km