In an election, there were only two candidates. The winning candidate got 48% of the total votes. His opponent got 6800 votes which was 34% of the total votes. Some of the votes were invalid. The winning margin of the candidate who won the election and the number of invalid votes respectively are:
1
3200 votes, 3600 votes
2
3000 votes, 3600 votes
3
2800 votes, 3600 votes
4
3600 votes, 2800 votes