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There are 5 chairs. Bob and Rachel want to sit such that Bob is always
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14 Jun 2020, 02:40
14 Jun 2020, 02:40
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Question Stats:
71% (01:03) correct
28% (00:46) wrong based on 21 sessions
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There are 5 chairs. Bob and Rachel want to sit such that Bob is always left to Rachel. How many ways it can be done?
10
10
Re: There are 5 chairs. Bob and Rachel want to sit such that Bob is always
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18 Jun 2020, 07:03
18 Jun 2020, 07:03
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Asmakan wrote:
There are 5 chairs. Bob and Rachel want to sit such that Bob is always left to Rachel. How many ways it can be done?
May someone explain the law of symmetry to solve this question?
May someone explain the law of symmetry to solve this question?
2 People can arrange themselves on 5 chairs in 5P2 ways or 2! * 5C2 ways
According to Law of symmetry
In half of the cases Bob will be left of Rachel i.e 10 cases
In Remaining half cases Bob will be to the right of Rachel i.e 10 cases
General Discussion
Re: There are 5 chairs. Bob and Rachel want to sit such that Bob is always
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15 Jun 2020, 08:55
15 Jun 2020, 08:55
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i think its 24, here is how i thought of it:
first list down how many different ways can bob be to the left of rachel:
1) B R x x x
2) x B R x x
3) x x B R x
4) x x x B R
so 4 ways, but in each one way, the other 3 people sitting can have there own permutation
so basically, 4 (ways for bob and rachel) x 6 (permutation of the other 3)
first list down how many different ways can bob be to the left of rachel:
1) B R x x x
2) x B R x x
3) x x B R x
4) x x x B R
so 4 ways, but in each one way, the other 3 people sitting can have there own permutation
so basically, 4 (ways for bob and rachel) x 6 (permutation of the other 3)
