Solution

154248

First name
Krishendhri ,Janagan,Nirushun,Kavishan
School
Bond primary
Country
Age
9

We think it's twelve because we did it systematically and it ended up like a chart .We tried it two times and the second time worked.We switched the numbers. Here are the answers.
5.11<5.23. 5.23>5.11
5.11<5.32. 5.32>5.11
5.12<5.13. 5.13>5.12
5.12<5.31. 5.31>5.12
5.13<5.21. 5.21>5.13
5.21<5.31. 5.31>5.21