How many different 3-digit numbers can be made from the digits 1, 2, 3 and 4 if each digit may be used at most once in a number?
Answer and explanation
Correct answer: B. 24
- Step 1: There are 4 choices for the hundreds digit. Step 2. Then 3 choices for the tens digit and 2 for the units digit. Step 3. 4 × 3 × 2 = 24. Answer: 24. Why not the others: 64: This allows digits to be repeated. 12: This counts only the first two digits, 4 × 3. 4: This counts the ways to choose three digits without arranging them.
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