Permutations and Combinations
How many -digit numbers can be formed by using the digits to if no digit is repeated?
Solution: A three digit number is to be formed from given digits .
Now, there are
ways to fill
Since repetition is not allowed, so place can be filled by the remaining digits.
So, tens place can be filled in ways.
Similarly, to fill of places, we have digits remaining.
So, hundreds can be filled by ways.
So, the required number of ways in which three-digit numbers can be formed from the given digits is