This Bible contradiction is from the Skeptic's Annotated Bible.
Verses
For many
Matthew 20:28 View context
Even as the Son of man came not to be ministered unto, but to minister, and to give his life a ransom for many.
Mark 10:45 View context
For even the Son of man came not to be ministered unto, but to minister, and to give his life a ransom for many.
For all
1 Timothy 2:6 View context
Who gave himself a ransom for all, to be testified in due time.