How many three-digit numbers have digits that add up to 3?
Answer and explanation
Correct answer: A. 6
- Step 1: List them by the hundreds digit. Step 2. With 1: 102, 111, 120. With 2: 201, 210. With 3: 300. Step 3. That is 3 + 2 + 1 = 6 numbers. Answer: 6. Why not the others: 4: This counts only the numbers whose digits are all different: 102, 120, 201 and 210. 5: This misses 300, where the digit 0 is repeated. 10: This also counts numbers that start with 0, such as 012, which are not three-digit numbers.
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