How many 3-digit numbers can be formed using digits 1, 2, 3, 4 (repetition not allowed)?
Solution
3-digit number: 4 choices for hundreds (can't be 0, and all different), then 3 for tens, 2 for units: 4×3×2 = 24.
About this question
Subject: Mathematics · Chapter: Permutations and Combinations · Topic: Fundamental Counting Principle
This question is part of PrepWiser's free JEE Main question bank. 16 more solved questions on Permutations and Combinations are available — start with the harder ones if your accuracy is >70%.