add any 3 odd numbers to get 30
This is very basic mathematics rule that sum of three odd can never be an even number.
But for this question there is a solution.
Take three odd numbers.
9+15+3!
3! is known as 3 factorial.
3! = 3.2.1= 6
When you add them,
9+15+3! = 9+15+6= 30
I hope this answer helps you.
Feel free to ask if you have any more queries.
All the best!