The no. of applicants for a job is 15. (i)Calculate the no. of ways in which 6 applicants can be selceted for the interview.
The six selected applicants on a particular day. (ii)Caluculate the no. of ways in which the order of the six interviews can be arranged.
Of the 6 applicants, 3 have backgrounds in business, 2 have backgrounds in education and 1 has a background in recreation. Calculate the number of ways in which the order of the 6 interviews can be arranged, when applicants having the same background are interviewed in succesion.
Who’s up for this challenge?
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Of the 6 applicants, 3 have backgrounds in business, 2 have backgrounds in education and 1 has a background in recreation. Calculate the number of ways in which the order of the 6 interviews can be arranged, when applicants having the same background are interviewed in succesion.
BBB EE RSo there are 3 groups of people and there are 3! ways of arranging these 3 groups
Within BBB group, there are 3! ways of arrange these 3 B people, similar within EE group, there are 2! ways of arrange these 2E people
so Total = Arrange Big Groups * Arrange within each group = 3! * 3! * 2!
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2 Comments for A-Math P & C Qn!
lijun(: | September 21, 2007 at 8:07 pm
hey..
my amaths really isn’t strong, so i hope you’ll help me and correct my mistakes. thanks.
anyway. here are my answers:
(i)no. of ways in which 6 applicants can be selceted for the interview = 15C6 = 5005
(ii)no. of ways in which the order of the six interviews can be arranged = 6! = 720
number of ways in which the order of the 6 interviews can be arranged, when applicants having the same background are interviewed in succesion = 3!X2!X3! = 72
i’m quite doubtful of the last answer. haha. but i decided to try anyway. (:
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