The president of a country and 4 other dignitaries are scheduled to sit in a row on 5 chairs. If the president must sit in the center chair, how many different seating arrangements are possible for the 5 people?
(A) 4
(B) 5
(C) 20
(D) 24
(E) 120
What is the fastest way to solve this question. Would 5*5 - 1 (the president, who must sit in the center chair) always work? The Answer would be [spoiler](D)[/spoiler].
seating arrangements question - fastest way to solve
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Xeb wrote:The president of a country and 4 other dignitaries are scheduled to sit in a row on 5 chairs. If the president must sit in the center chair, how many different seating arrangements are possible for the 5 people?
(A) 4
(B) 5
(C) 20
(D) 24
(E) 120
What is the fastest way to solve this question. Would 5*5 - 1 (the president, who must sit in the center chair) always work? The Answer would be [spoiler](D)[/spoiler].
Xeb,
24 is right, but 5*5-1 is not a legitimate way to get there.
Think about the case where there are 2 dignitaries and 1 president with the same restriction of the president having to sit in the middle. If we represent the dignitaries by A and B, the possible orders are APB and BPA. Only two ways. Whereas your method would give 3*3-1=8.