At 7 a.m., Ahmad started from City Q and travelled towards City R and his speed remained constant throughout. At 9 a.m., Natalie started her journey from City Q towards City R at an average speed of 84 km/h. Natalie overtook Ahmad at 1 p.m. After overtaking, Natalie carried on her journey at the same average speed and reached at City R at 3:15 p.m.

1. Find Ahmad'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 Natalie had travelled until Natalie overtook Ahmad
= 4 x 84
= 336 km

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

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

(b)
From 9 a.m. to 3:15 p.m. = 6 h 15 min

1 h = 60 min
6 h 15 min = 6 ¹⁵ ₆₀
 h = 6 ¹₄ h

Distance between the two cities
= 6 ¹₄ x 84
= ²⁵₄ x 84
= 525 km

Answer(s): (a) 56 km/h; (b) 525 km