Ten unit steps from 0 ending at 4
Question
Count the sequences of numbers such that , , and each consecutive pair differs by exactly one, that is for .
Short answer
. Each step is or ; to net in steps you need up-steps and down-steps. Choosing where the down-steps go gives .
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Open the worked solutionLessons behind this question
- Counting and Combinatorics
- Sample Spaces, Events, and the Probability Axioms
- Conditional Probability, Total Probability, and Bayes' Rule
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