How many three digit numbers can be formed without using the digits 0,2,3,4,5 and 6?

Explanation

To solve the problem of how many three-digit numbers can be formed without using the digits 0, 2, 3, 4, 5, and 6, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Available Digits**:
The digits we can use are 1, 7, 8, and 9. This gives us a total of 4 usable digits.

2. **Understand the Structure of a Three-Digit Number**:
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