At 8 a.m., Elijah started from City N and travelled towards City P and his speed remained constant throughout. At 9 a.m., Tammy started her journey from City N towards City P at an average speed of 78 km/h. Tammy overtook Elijah at 2 p.m. After overtaking, Tammy carried on her journey at the same average speed and reached at City P at 4:50 p.m.
- Find Elijah'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 Tammy had travelled until Tammy overtook Elijah
= 5 x 78
= 390 km
From 8 a.m. to 2 p.m. = 6 h
Elijah's average speed
= 390 ÷ 6
= 65 km/h
(b)
From 9 a.m. to 4:50 p.m. = 7 h 50 min
1 h = 60 min
7 h 50 min = 7
50 60
h = 7
56 h
Distance between the two cities
= 7
56 x 78
=
476 x 78
= 611 km
Answer(s): (a) 65 km/h; (b) 611 km