Definition: Given the Question and Answer pair, detect whether the answer is acceptable or not. Denote acceptable answer as "yes", otherwise denote as "no". An acceptable answer is consistent with the context in question, detailed, long, and uses general knowledge of English. Answers that are not definite and suggest a variety of options are not acceptable answers.
Input: Question: I just realized that I've never needed to use 31th or 31st in my four years English study. So which one is correct, and what about other alternatives? 31th or 31st 101th or 101st 1001th or 1001st Can I also use that way everywhere in the same way (for example, ordinal numbers in math)? 
Answer: The numerals with endings are merely abbreviations for the words written out as text. When in doubt, write the word out. Thirty-first becomes 31st, eleventh 11th, forty-second 42nd, fiftieth 50th, and so on.

yes