At 8 a.m., Tommy started from City N and travelled towards City P and his speed remained constant throughout. At 10 a.m., Diana started her journey from City N towards City P at an average speed of 84 km/h. Diana overtook Tommy at 2 p.m. After overtaking, Diana carried on her journey at the same average speed and reached at City P at 1:50 p.m.

1. Find Tommy'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 Diana had travelled until Diana overtook Tommy
= 4 x 84
= 336 km

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

Tommy's average speed
= 336 ÷ 6
= 56 km/h

(b)
From 10 a.m. to 1:50 p.m. = 3 h 50 min

1 h = 60 min
3 h 50 min = 3 ⁵⁰ ₆₀
 h = 3 ⁵₆ h

Distance between the two cities
= 3 ⁵₆ x 84
= ²³₆ x 84
= 322 km

Answer(s): (a) 56 km/h; (b) 322 km