Whether or not you want to choose maths+biology after your 10th standard is completely your choice. However, let me be frank with you regarding the stress levels that you'd have to face if you do so.
Firstly, you will have to focus on two vast subjects and give the same time to both the subjects while a normal person would dedicate the same amount of time to just one subject.
Secondly, you can choose maths and biology depending upon the career that you propose to choose. If it demands either of these subjects, there is logically no need to do the other. Instead, you can concentrate on just one subject.
However, If your academics are exceptionally well, then congratulations! Maths+biology is for you!
Hope this helps.
Do let me know if there's something else I can hep you with.