At 7 a.m., Eric started from City T and travelled towards City U and his speed remained constant throughout. At 8 a.m., Emma started her journey from City T towards City U at an average speed of 84 km/h. Emma overtook Eric at 1 p.m. After overtaking, Emma carried on her journey at the same average speed and reached at City U at 3:50 p.m.

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

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

Distance that Emma had travelled until Emma overtook Eric
= 5 x 84
= 420 km

From 7 a.m. to 1 p.m. = 6 h

Eric's average speed
= 420 ÷ 6
= 70 km/h

(b)
From 8 a.m. to 3:50 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 84
= ⁴⁷₆ x 84
= 658 km

Answer(s): (a) 70 km/h; (b) 658 km