Geometry

Question Analysis
This question involves calculating permutations where repetition is allowed.
The main focus is on applying the formula , where is the number of options for each position and is the number of positions.

Key Concept Explanation
When repetition is allowed in a permutation problem, for each of the positions, there are choices. The formula gives the total number of possible arrangements.
Here, represents the number of available elements (e.g., digits on a lock), and represents the number of selections (e.g., number of digits in the code).

Step - by - Step Solution
For the combination lock,