This Bible contradiction is from the Skeptic's Annotated Bible.

Verses

Yes, since he had already appeared to Simon.

Luke 24:33-34 View context

And they rose up the same hour, and returned to Jerusalem, and found the eleven gathered together, and them that were with them,

Saying, The Lord is risen indeed, and hath appeared to Simon.

No.

Mark 16:12-13 View context

After that he appeared in another form unto two of them, as they walked, and went into the country.

And they went and told [it] unto the residue: neither believed they them.