Bryan, Wesley and Tom started walking at the same time from the same starting point round a circular track. Tom walked in the clockwise direction. Bryan and Wesley walked in an anti-clockwise direction. Tom took 6 min to complete each round. He met Bryan after every 2 minutes. He met Wesley after every 5 minutes. The three friends kept to their respective speeds throughout their walk.

1. How many rounds did Tom complete in 1 h?
2. When Tom and Bryan met again at the starting point after 1 h, Wesley had completed 1.5 km. Find the circumference of the circular track in metres.

(a)
1 h = 60 min

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

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

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

Tom's distance : Bryan's distance
2 : 6 - 2
2 : 4

Tom's distance : Wesley's distance
5 : 6 - 5
5 : 1

Tom	Bryan	Wesley
2x5	4x5
5x2		1x2
10	20	2

The distance of Tom is the repeated identity. 
LCM of 2 and 5 = 10

In 1 h
Tom's rounds : Bryan's rounds : Wesley's rounds
10 : 20 : 2

Distance that Wesley completed in 1 h = 1.5 km

2 rounds = 1.5 km = 1500 m

1 round = 1500 ÷ 2 = 750 m

Circumference of the circular track = 750 m

Answer(s): (a) 10; (b) 750 m