yes its possible

Yes it is possible but you have to give different alias name to the web method so that ambiguity can be avoided

---method will be call from application by the name AddInt
[WebMethod Name ="AddInt"]
public void Add(){}//implement code for adding 2 int variable

---------In this step even if you dont give name attribute  it will work and method will be called by name Add.
[WebMethod Name ="AddFloat"]
public void Add(){}//implement code for adding 2 float variable

else it will give error