onclick on random objects in gamemode and update score

Here I want to Choose a correct DYNAMIC RANDOM Object answer,compare two objects in monitor mouse position and select the correct object means update a score.am stuck with if ((hit.collider.gameObject).Equals(dub)) help me,

using UnityEngine; using System.Collections; using UnityEngine.UI; using System.Collections.Generic;

public class Rannum : MonoBehaviour { private TextMesh rnum; public TextMesh ans; public TextMesh anss; private TextMesh ansd1; private TextMesh ansd2; public GameObject[] aa; public GameObject dub; public RaycastHit hit;

 void Start () 
 
 {
             int n;
             n = Random.Range (1, 100);
             print (n);
             GameObject texq = GameObject.Find ("TextQ");
             rnum = texq.GetComponent<TextMesh> (); 
             rnum.text = "Number:" + n;

             int x = n;
             int y = (x / 3);
             int z = x - y;
             print (y);
             print (z);
             int n1 = (n - 1);
             int d1 = (n1 / 3);                                                
             int d2 = n1 - d1;
             int d3 = Random.Range (0, 50);
     
             int index = Random.Range (0, aa.Length);
             print ("index:"+index);
             //int a = 0;int b = 1;int c = 2;
     
             GameObject t1 = GameObject.Find ("Text1");
             GameObject t2 = GameObject.Find ("Text2");
             GameObject t3 = GameObject.Find ("Text3");
             
             
         
             if (index < 1) {
         
                     ansd1 = t2.GetComponent<TextMesh> (); 
                     ansd1.text = +y + "+" + d3;
         
                     ansd2 = t3 .GetComponent<TextMesh> (); 
                     ansd2.text = +d1 + "+" + d2;
             }
     
             if (index > 0 || index < 2) {
         
                     ansd1 = t1.GetComponent<TextMesh> (); 
                     ansd1.text = +y + "+" + d3;
         
                     ansd2 = t3.GetComponent<TextMesh> (); 
                     ansd2.text = +d1 + "+" + d2;
             }    
     
             if (index > 1) {
         
                     ansd1 = t1.GetComponent<TextMesh> (); 
                     ansd1.text = +y + "+" + d3;
         
                     ansd2 = t2.GetComponent<TextMesh> (); 
                     ansd2.text = +d1 + "+" + d2;
     }    
     dub = aa [index];
     ans = dub.GetComponent<TextMesh> (); 
     ans.text = +z + "+" + y;
     }
 void Update()
 {
     if (Input.GetMouseButtonDown (1)) {
                     Application.LoadLevel (0);
             }
             Ray ray = camera.ScreenPointToRay (Input.mousePosition);
             
         if (Input.GetMouseButtonDown (0)) 
             { 
                 if (Physics.Raycast (ray, out hit, 10))
                         {
                             if ((hit.collider.gameObject).Equals(dub))
                             
                             {    print ("write the code for score...!!!");}
                             else {  print("loose");    }
                 
                         }
             }
 }    

}