1. **Problem statement:**
Freddie has a 6-digit code with no repeated digits and the first digit is not zero.
(i) Find the number of such 6-digit numbers.
(ii) Find the number of such 6-digit numbers divisible by 5.
2. **Step (i): Number of 6-digit numbers with no repeated digits and first digit not zero**
- The first digit can be any digit from 1 to 9 (9 options).
- The second digit can be any digit except the first digit (9 options, including zero now).
- The third digit can be any digit except the first two digits (8 options).
- The fourth digit: 7 options.
- The fifth digit: 6 options.
- The sixth digit: 5 options.
So total numbers = $9 \times 9 \times 8 \times 7 \times 6 \times 5$
3. **Step (ii): Number of such 6-digit numbers divisible by 5**
- A number divisible by 5 ends with 0 or 5.
- Case 1: Last digit is 0
- First digit: 9 options (1-9)
- Last digit fixed as 0
- Remaining 4 digits: choose from 8 remaining digits (excluding first digit and 0)
- So number of ways = $9 \times P(8,4) = 9 \times 8 \times 7 \times 6 \times 5$
- Case 2: Last digit is 5
- First digit: 8 options (1-9 except 5)
- Last digit fixed as 5
- Remaining 4 digits: choose from 8 remaining digits (excluding first digit and 5)
- Number of ways = $8 \times P(8,4) = 8 \times 8 \times 7 \times 6 \times 5$
- Total numbers divisible by 5 = Case 1 + Case 2
4. **Calculations:**
- Step (i): $9 \times 9 \times 8 \times 7 \times 6 \times 5 = 136080$
- Step (ii):
- Case 1: $9 \times 8 \times 7 \times 6 \times 5 = 15120$
- Case 2: $8 \times 8 \times 7 \times 6 \times 5 = 13440$
- Total = $15120 + 13440 = 28560$
**Final answers:**
(i) $136080$
(ii) $28560$
6 Digit Codes 092Bd3
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