While walking along the river, you come upon a countess. The countess looks very sad, so you ask what is wrong. It seems that the countess has lost some numbers and needs to find them. She says they are special numbers because:
- They are all between 300 and 600.
- The middle digit is odd and the other digits are even.
- The sum of the digits is 13.
Can you find the lost numbers for the countess?
![](https://sawanonlinebookstore.com/wp-content/uploads/2022/06/108-420x1024.jpg)
Answer
The lost numbers are 418, 436, 454, 472 and 490.
Try 3-digit numbers that begin with 4 and have an odd middle number and an even ones digit. Then add the digits to see if the sum is 13.