Yes you can choose mathematics as elective it has no relation to your subjects in your intermediate. If you think you can do good in it then you can choose it.

Hello,

As per your query you was not having mathematics as your subject in the 12th. Now, you want to choose mathematics as an elective subject in bsc semester 3rd...
Let me tell you that there is nothing to worry for that!!! In the 3rd semester you will be offered different elective subjects including computer, chemistry, mathematics and many more... Now, if you want to choose mathematics then its totally your choice.... You can choose mathematics as an elective subject in bsc semester 3rd....

And frankly speaking, mathematics is not that tough subject as we think it is!!! It totally depends on your hardwork and how keen you are to learn it!!!!

Wish you all the best!!!!

I hope this would help you. For further queries please feel free to write me down in the comment box.