what 3 delegates refused to sign the constitution because it did not have a ???

Answer 1

didnt have a . . . bill of rights? i dont get ur ?.

Answer 2

The total number to ever attend the Convention is irrelevant here (though some of those who left did so because they disagreed with it). Only three present *on the day of the signing* refused to sign:

George Mason and Edmund Randolph of Virginia
Elbridge Gerry of Massachusetts
http://www.constitutioncenter.org/explore/FoundingFathers/index.shtml

In case you're interesting in ALL who were delegates but did not sign the document, here is a table listing these sixteen men, with some info about each:
http://www.history.army.mil/books/RevWar/ss/appc.htm

I will assume that you intended to write "... did not have a Bill of Rights". But I do not believe this is quite accurate. Of the three:

George Mason certainly regarded this as a CENTRAL issue.
http://www.constitutioncenter.org/explore/FoundingFathers/Virginia.shtml#mason

Elbridge Gerry listed this as ONE of his objections --not sure it was "the key". He DID think its defects could be adequately cured by proper amendments.
http://memory.loc.gov/learn/features/timeline/newnatn/usconst/egerry.html

Edmund Randolph objected on other grounds, viz. that the "Republican propositions" of the Virginia Plan had "much to his regret been widely, and in his opinion, irreconcilably departed from."
But he changed his mind and argued FOR ratification at the Virginia Ratifying Convention, providing as his reason, "The accession of eight states reduced our deliberations to the single question of Union or no Union."
http://teachingamericanhistory.org/convention/delegates/randolph.html

Answer 3

Is this a riddle or a question?