Is the given collection a set or not?
All difficult problems in your book on Mathematics.
No, it is not a set because the term difficult is not well-defined.
State whether the given collection is a set or not:
A collection of all easy problems in your mathematics book.
A collection of difficult questions in your mathematics book is a set.
Check the given collection is set? If not a set, give reason
All difficult problems in your Math book
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