How do I do I time-base score script

I need to access two script . I need to keep up with timer and the score when the timer reach zero . I think playerprefs will work. I don't know how to approach this . Here is my timer script and my score script .

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

public class ScoreManager : MonoBehaviour { public static int score; private Text text;

  void Awake () 
  {    
      text = GetComponent <Text> ();
      score = 0;


  
  }
 
  void Update ()
 {
          text.text = "Score :" + score;
      }
  
  

}

using UnityEngine; using UnityEngine.UI; using UnityEngine.SceneManagement;

public class MyClock : MonoBehaviour { public string time; public int Minutes = 0; public int Seconds = 0;

   private Text    m_text;
   private float   m_leftTime;
  
   private void Start()
   {

       m_text = GetComponent<Text>();
       m_leftTime = GetInitialTime();
   }
  
   public void Update()
   {
       if (m_leftTime > 0f)
       {


           //  Update countdown clock
           m_leftTime -= Time.deltaTime;
           Minutes = GetLeftMinutes();
           Seconds = GetLeftSeconds();

           //  Show current clock
           if (m_leftTime > 0f)
           {
                             
               m_text.text = "Time : " + Minutes + ":" + Seconds.ToString("00");
           }
           else
           {
               //  The countdown clock has finished
               m_text.text = "Time : 0:00";
           }
       }
   }
  
   private float GetInitialTime()
   {
       return Minutes * 60f + Seconds;
   }
  
   private int GetLeftMinutes()
   {
       return Mathf.FloorToInt(m_leftTime / 60f);
   }
  
   private int GetLeftSeconds()
   {
       return Mathf.FloorToInt(m_leftTime % 60f);
   }

}