At 8 a.m., Simon started from City X and travelled towards City Y and his speed remained constant throughout. At 10 a.m., Barbara started her journey from City X towards City Y at an average speed of 90 km/h. Barbara overtook Simon at 2 p.m. After overtaking, Barbara carried on her journey at the same average speed and reached at City Y at 2:50 p.m.

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

(a)
From 10 a.m. to 2 p.m. = 4 h

Distance that Barbara had travelled until Barbara overtook Simon
= 4 x 90
= 360 km

From 8 a.m. to 2 p.m. = 6 h

Simon's average speed
= 360 ÷ 6
= 60 km/h

(b)
From 10 a.m. to 2:50 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 90
= ²⁹₆ x 90
= 435 km

Answer(s): (a) 60 km/h; (b) 435 km