Find the sum of all four digit numbers that can be formed by the digits 1, 3, 5, 7, 9 without repetition. A. 666600 B. 665500 C. 666700 D. 678860 Answer Workspace Report Discuss Answer with explanation Answer: Option A Explanation Explanation: The given digits are 1, 3, 5, 7, 9 Sum of r digit number= n-1Pr-1 (Sum of all n digits)×(1111… r times) N is the number of non zero digits. Here n=5, r=4 The sum of 4 digit numbers 4P3 (1+3+5+7+9)(1111)=666600. Workspace
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