We are asked to find the number of 3-digit integers greater than 430 that can be formed using the digits 0, 1, 2, 3, 4, and 5, where repetition of digits is allowed.
2025/6/18
1. Problem Description
We are asked to find the number of 3-digit integers greater than 430 that can be formed using the digits 0, 1, 2, 3, 4, and 5, where repetition of digits is allowed.
2. Solution Steps
Let the 3-digit integer be represented as , where .
Since the number must be greater than 430, we consider the possible values for :
* Case 1: . Then , or and .
* If and , there are 2 choices for . Then can be any of the 6 digits . So there are possibilities.
* If and , then must be greater than
0. $c \in \{1, 2, 3, 4, 5\}$. So there are 5 choices for $c$.
So, when , the number of possibilities is .
* Case 2: . Then and can be any of the 6 digits.
* If , there are 6 choices for and 6 choices for . So there are possibilities.
* Case 3: . These are not possible, because the number must be greater than
4
3
0.
* Case 4: If the number is a 3 digit number, the first digit cannot be zero. Hence, can be chosen from the set .
The total number of 3-digit integers greater than 430 is the sum of the possibilities from the above cases.
Total possibilities = .
3. Final Answer
53