Yes, it can be. Check the example below.

       [WebMethod(MessageName = "AddInt")] 
	public int Add(int a, int b) 
	{ 
		return (a + b); 
	} 
	[WebMethod(MessageName = "AddFloat")] 
	public float Add(float a, float b) 
	{ 
        	return (a + b); 
	}