Question

At 5.45p.M .,lixin,khairul and Devil are at the starting point of a 1-km circular path. Lixin Takes 18 minutes to walk one round ,khairul needs 360 seconds to run 1 round ansd Devi cycles 2 rounds in 4 minutes .Find the time when all three of them will next meet

Answer 1

`Meeting\ Time = 6:03\ pm`

Explanation:

Given

`Start\ Time= 5:45pm`

`Lixin = 18\ min/round`

`Khairul = 360\ seconds/round`

`Devi = 4minutes/2\ rounds`

Required

Determine their next meeting time

First, we need to get their unit rate in minutes per round

`Lixin = 18\ min/round`

`Khairul = 360\ seconds/round`

Convert 360 seconds to minutes

`Khairul = (360)/(60) min/round`

`Khairul = 6 min/round`

`Devi = 4minutes/2\ rounds`

Divide by 2/2

`Devi = 2mins/round`

So, we have:

`Lixin = 18\ min/round`

`Khairul = 6 min/round`

`Devi = 2mins/round`

Next, is to determine the LCM of 18, 6 and 2

`18=2 * 3 * 3`

`6 = 2 * 3`

`3 = 3`

Their LCM is:

`LCM = 2 * 3 * 3`

`LCM = 18`

This means that they will meet 18 minutes after their initial time of departure.

So:

`Meeting\ Time = 5:45\ pm + 18\ minutes`

`Meeting\ Time = 6:03\ pm`