Permutations with repetition - practice problems

Permutations with repetition count arrangements where some objects are identical, reducing the total number of distinct permutations. When arranging n objects where n₁ are of one type, n₂ of another, and so on, the formula is n!/(n₁!n₂!...nₖ!). For example, the word "MISSISSIPPI" has 11 letters with repetitions, giving 11!/(4!4!2!) distinct arrangements. This differs from standard permutations where all objects are unique. When unlimited repetition is allowed (like selecting with replacement), k items chosen from n options give n^k permutations. Applications include counting distinct arrangements of letters in words, distributing identical objects, and analyzing sequences with repeated elements. Understanding this concept is essential for advanced combinatorics and probability calculations.

Directions: Solve each problem carefully. Show all your work.

Number of problems found: 39


Do you have unsolved math question and you need help? Ask a question, and we will try to solve it. We solve math question.



Solved math problems are published at new problems.

Do not submit problems from ongoing competitions, including Mathematical Olympiads and correspondence seminars.