1. No one wants to work with dirty,smelly people.

2. No one wants to work with dirty smelly people.

3. No one wants to work with dirty and smelly people.
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Which ones are grammatical? In #1, a comma was used before 'people.' In Sentence 2, no comma was used. In Sentence 3, 'and' was used.

#1 is correct, with the comma between dirty and smelly. #3 is also correct. #2 is not.