Doc Freemo 
A nice little challenge for the day. Attached is the image for the question/challenge. A few notes
1) you must fill in all the boxes
2) you can not add any symbols into the box other than the provided numbers.
3) you cant use a trick of the wording to solve this, it must be solved with mathematical trickery
4) the answer is not "no" there is an actual solution by picking 3 numbers.
Solution, maybe cheating
@khird you filled int he box with 10's though not 11's, 30 doesnt exist in binary base.
Solution, maybe cheating
@freemo I never used binary, only bases nine and ten (decimal).
11₉ + 11₉ + 11₉
= 10₁₀ + 10₁₀ + 10₁₀
= 30₁₀ = 30
Solution, maybe cheating
@khird It the mixing of bases that is more the issue.
Solution, maybe cheating
@khird Can you do it with consistent bases across the whoe equation?
Solution, maybe cheating
@freemo You mean that if I interpret the boxed numbers as a certain base, I have to do the same for the 30 so as not to mix bases?
Interpreting everything in base nine:
11 + 11 + 7 = 30
The decimal interpretation would be:
10 + 10 + 7 = 27
Solution, maybe cheating
@khird There ya go :) other bases also work but thats one answer :)
Well there isn't a solution if you using only those numbers.
One can use decimal number instead or use algebra or pre calculus formula.
@inditoot There is a solution. Since you cant use anything but those numbers algebra and pre calc aren't options. I see no issue with using decimal numbers though, thats what most people assume anyway, or did you mean binary? You'd be welcome to use binary here except 30 is not a binary number so you cant (binary only has 1 or 0's in it)
What about using factorial of an number? 
@inditoot That would be a mathematical operator. The only thing you can put in those boxes are the numbers listed.
I need solution now 
Solution
13 + 11 + 1 = 30
the numbers were base 5 numbers. Though solutions in other bases (like base 9) also work so there are multiple answers.
Solution
Solution to these questions are never funny
@inditoot Would you like the solution?
solution, probably cheating
solution, probably cheating
@hushroom Creative, though not the intended answer :)
@freemo +15+15 (just fill the first box with nothing)
@vovanium rule #1, you must fill all the boxes with numbers
@freemo there's no word 'number' in the (original) rule #1 :)
@freemo There's also a solution exists with 9, 9 and 15 (in any order), but one of 9's should be rotated by \[\frac{\pi}{2}\]
@freemo by \[\pi\] sorry :)
@freemo Taking these numbers to be written in base ten, there is no solution.
You cannot add three odd numbers into an even number.
@kallisti Your assumption was not stated as a rule :)
Solution, maybe cheating
@freemo
Each box can be filled with 11₉ which is equal to 10 in decimal. 10 + 10 + 10 = 30.