Discrete Structures20815 marksNumerical: permutations, digit arrangementPermutations and Combinations
When do we use permutation rather than combination? How many 5-digit numbers can be generated using the digits 0 to 9, if each number starts with 98 and no digit appears more than once?
When do we use permutation rather than combination? How many 5-digit numbers can be generated using the digits 0 to 9, if each number starts with 98 and no digit appears more than once? [5]
We use a permutation when the order of arrangement matters, i.e., when different orderings of the same selected items are counted as distinct outcomes. We use a combination when only the selection matters and order is irrelevant. Formulas: - Permutation: $P(n, r) = \dfrac{n!}{(n-r)!}$ (order matt...