There were 6 numbers of the same family.
One of them ran away.
Please catch it and prove it belongs to the original set.
The remaining five are:
- 2,367,143
- 5,713,643
- 4,437,136
- 3,433,671
- 6,714,336
ENJOY!
1) Ignore the first digit, initially.
2) Then each number has the same 6 digits in some order: 133467.
3) And each column (place) has 2 pairs and an unmatched digit. If the sixth number ends in 364371 then each column has 3 pairs in it. So that is the ending of the missing number.
4) But what is the first digit? Order the five 7 digit numbers, giving:
2,367,143
3,433,671
4,437,136
5,713,643
6,714,336
We observe that sorting by the first digit also sorts by the last six.
Since 364371 is less than 367143, the missing number must be first, making it 1,364,371
Solution, with explanation
