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प्रश्न
- In how many ways can 8 identical beads be strung on a necklace?
- In how many ways can 8 boys form a ring?
उत्तर
- Number of ways 8 identical beads can be stringed by `((8 - 1)!)/2 = (7!)/2`
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Number of ways 8 boys form a ring = (8 – 1)! = 7!
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