what does negation mean?helppppp

is there is a statement a, is negation means the opponent view of a, or sth have a similar meaning as a?
like for the statement 'all multiples of 5 is odd', is the negation 'no multiple of 5 is even ' or 'at least one multiple of 5 is even'?
anyone can help me?

Negation of "all multiples of 5 are odd" is "at least one multiple of 5 is even".

If you look at 'all multiples of 5 is odd', and 'no multiple of 5 is even '. These statements say the same thing.

OK，it seems that the edexel book answer is wrong again

Ok

Those aren't the original question you asked, and none of those answers are negations. Do you have their definition of "negation"?

this is my original question and its answer. and our definition seems correct. I think it is just the mark scheme "s problem