This question bothers on permutation since we are to select a some people out of a group of people and then arrange in a straight line. If r object are to be arranged in a straight line when selecting them from n pool of objects. This can be done in nPr number of ways.
nPr = n!/(n-r)!
Selection of 6 people out of 8 people can therefore be done in 8C6 number of ways.
8P6 = 8!/(8-6)!
8P6 = 8!/2!
8P6 = 8*7*6*5*4*3*2!/2!
8P6 = 8*7*6*5*4*3
8P6 = 56*360
8P6 = 20,160
<em>Hence this can be done in 20,160 number of ways</em>
