Are you asking that because you are scared you won't make it in or because you don't think that combination is good?
If you are scared, don't worry. Then would consider you for your 2nd preference, (if you don't make it into your 2nd preference as well, they will consider the 3rd and so on..).
If it's because you don't believe it's a good combination, you can also go back to studying one of the single degrees.