At 8 a.m., Perry started from City Q and travelled towards City R and his speed remained constant throughout. At 9 a.m., Erika started her journey from City Q towards City R at an average speed of 66 km/h. Erika overtook Perry at 2 p.m. After overtaking, Erika carried on her journey at the same average speed and reached at City R at 1:50 p.m.
- Find Perry'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 Erika had travelled until Erika overtook Perry
= 5 x 66
= 330 km
From 8 a.m. to 2 p.m. = 6 h
Perry's average speed
= 330 ÷ 6
= 55 km/h
(b)
From 9 a.m. to 1:50 p.m. = 4 h 50 min
1 h = 60 min
4 h 50 min = 4
50 60
h = 4
56 h
Distance between the two cities
= 4
56 x 66
=
296 x 66
= 319 km
Answer(s): (a) 55 km/h; (b) 319 km