which one is correct?

i saw on pster that read : ” 22th festival ” but i have learned that it should be ” 22nd “. are both forms correct ?
Answer #1
22nd is correct. 22th does not exist. People make a lots of mistake on this. It even sound wrong if you think about it. 22nd (twenty second) and 22th (twenty two th)
Heres an example for future reference.
1=1st
2=2nd
3=3rd
4=4th then this rule applicable till 20th (5th , 6th, 7th, 8th, 9th, 10th, 11th and 20th etc)
We follow those rule.
31st 32nd 33rd 34th
Hope you understand man.
Just pull this off wiki and I think it explain better than me lol
    -st is used with numbers ending in 1 (e.g. 1st, pronounced first)
    -nd is used with numbers ending in 2 (e.g. 92nd, pronounced ninety-second)
    -rd is used with numbers ending in 3 (e.g. 33rd, pronounced thirty-third)
    As an exception to the above rules, all the "teen" numbers ending with 11, 12 or 13 use -th (e.g. 11th, pronounced eleventh, 112th, pronounced one hundred [and] twelfth)
    -th is used for all other numbers (e.g. 9th, pronounced ninth).
Answer #2
yes i know and thanks for the explanation. i was just confused how a poster on a scientific subject which was held in a university could make such a mistake.
Answer #3
we are all human and most of us make silly mistakes at times – i worked for a university many many years ago , we had an undergraduate take some machinery out into the field , a week later he bought it back and said the f’n thing had not worked from day 1 , i asked did you put petrol in the whiper snipper , he said ” um no i didnt even know it used fuel ” , this guy was in his late 20’s
Answer #4
22nd should be the only correct form
Answer #5
It’s 20th + 2
Answer #6
It's 20th + 2
of course it is