How many different three-digit codes can be created from the digits 0, 1, 4, 8, and 9 if no digit may be repeated in any code?

A. 12
B. 15
C. 60
D. 120



Answer :

To determine how many different three-digit codes can be created from the digits 0, 1, 4, 8, and 9, given that no digit may be repeated in any code, we can follow these steps:

1. Identify the Total Number of Digits Available:
The given digits are 0, 1, 4, 8, and 9. Hence, there are 5 different digits in total.

2. Permutations of 3 Digits:
Since we need to create three-digit codes and each digit cannot be repeated, we use permutations.

The formula to calculate the number of permutations of \( n \) items taken \( r \) at a time is:
[tex]\[ P(n, r) = \frac{n!}{(n - r)!} \][/tex]
Where:
- \( n \) is the total number of items,
- \( r \) is the number of items to choose, and
- \( ! \) denotes factorial.

3. Substitute the Values:
Here, \( n = 5 \) (since we have 5 digits) and \( r = 3 \) (since we need a three-digit code). So we calculate:
[tex]\[ P(5, 3) = \frac{5!}{(5 - 3)!} = \frac{5!}{2!} \][/tex]
Calculate the factorials:
[tex]\[ 5! = 5 \times 4 \times 3 \times 2 \times 1 = 120 \][/tex]
[tex]\[ 2! = 2 \times 1 = 2 \][/tex]
Then, the number of permutations is:
[tex]\[ P(5, 3) = \frac{120}{2} = 60 \][/tex]

Therefore, the number of different three-digit codes that can be created from the digits 0, 1, 4, 8, and 9, without repeating any digit, is 60.

Thus, the correct answer is C. 60.