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| Math Central | Quandaries & Queries |
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Question from Tina, a parent: The sum of the digits of a 3-digit odd number is 13. The digit in the tens place is 4 less than the digit in the hundreds place and 3 more than the ones digit. What is the number? |
Hi Tina,
I am going to write the possible candidates for your 3 digit number starting with the digit in the hundredth place.
| 9 |
| 8 |
| 7 |
| 6 |
| 5 |
| 4 |
| 3 |
| 2 |
| 1 |
Now add the digit in the tens place. It is 4 less than the digit in the hundredth place so the possibilities are
| 9 | 5 |
| 8 | 4 |
| 7 | 3 |
| 6 | 2 |
| 5 | 1 |
| 4 | 0 |
A hundredths digit of 3, 2 or 1 is not possible since 4 less than any of these digits is not a digit.
The digit in the tens place is 3 more than the digit in the ones place so what are the possibilities for the three digit number? Which one has 13 as the sum of its digits?
Penny
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