At 8 a.m., Perry started from City V and travelled towards City W and his speed remained constant throughout. At 9 a.m., Gabby started her journey from City V towards City W at an average speed of 90 km/h. Gabby overtook Perry at 1 p.m. After overtaking, Gabby carried on her journey at the same average speed and reached at City W at 6:20 p.m.

1. Find Perry's average speed in km/h.
2. What is the distance between the two cities?

(a)
From 9 a.m. to 1 p.m. = 4 h

Distance that Gabby had travelled until Gabby overtook Perry
= 4 x 90
= 360 km

From 8 a.m. to 1 p.m. = 5 h

Perry's average speed
= 360 ÷ 5
= 72 km/h

(b)
From 9 a.m. to 6:20 p.m. = 9 h 20 min

1 h = 60 min
9 h 20 min = 9 ²⁰ ₆₀
 h = 9 ¹₃ h

Distance between the two cities
= 9 ¹₃ x 90
= ²⁸₃ x 90
= 840 km

Answer(s): (a) 72 km/h; (b) 840 km