The total number of permutations of n ( > 1 ) different things taken not more than r at a time, when…

The total number of permutations of n(>1) different things taken not more than r at a time, when each thing may be repeated any number of times is
  1. n(nn-1)n-1
  2. nr-1n-1
  3. n(nr-1)n-1
  4. None of these

Solution

When we arrange one things at a time, the number of possible permutations is n. When we arrange them two at a time the number of possible permutations are n×n=n2

and so on. Thus, the total number of permutations are

n+n2+....+nr=n(nr-1)n-1   (n>1)

Asked in: AP EAMCET 2022 (04 Jul Shift 1)

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