Cody, Ahmad and Wesley started walking at the same time from the same starting point round a circular track. Wesley walked in the clockwise direction. Cody and Ahmad walked in an anti-clockwise direction. Wesley took 6 min to complete each round. He met Cody after every 2 minutes. He met Ahmad after every 4 minutes. The three friends kept to their respective speeds throughout their walk.

1. How many rounds did Wesley complete in 1 h?
2. When Wesley and Cody met again at the starting point after 1 h, Ahmad had completed 1.2 km. Find the circumference of the circular track in metres.

(a)
1 h = 60 min

Number of rounds that Wesley completed in 1 h
= 60 ÷ 6
= 10

(b)
Wesley took 6 min to complete 1 round
1 min = ¹₆ of circular track = 1 u
6 min = ⁶₆ of circular track = 6 u

Wesley's distance is the repeated identity.
Make Wesley's distance the same.

Wesley's distance : Cody's distance
2 : 6 - 2
2 : 4

Wesley's distance : Ahmad's distance
4 : 6 - 4
4 : 2

Wesley	Cody	Ahmad
2x2	4x2
4x1		2x1
4	8	2

The distance of Wesley is the repeated identity. 
LCM of 2 and 4 = 4

In 1 h
Wesley's rounds : Cody's rounds : Ahmad's rounds
4 : 8 : 2

Distance that Ahmad completed in 1 h = 1.2 km

2 rounds = 1.2 km = 1200 m

1 round = 1200 ÷ 2 = 600 m

Circumference of the circular track = 600 m

Answer(s): (a) 10; (b) 600 m