how to get remaining time in a count down timer as a score?

Hello i’m new at using unity and i’m making a game, please I want to know how to get the remaining value of the timer and get it as a score. I have a treasure chest that when the player collides with it a GUI will appear and there’s a text (the question) and 4 buttons (multiple choices) with a timer of 10 seconds that counts down to 0. (ex. If the player answered correct with a remaining time of 5 he will get a score of 5)

Assuming you already have the script to show the UI, and you’re using C# and uGUI (the new gui). Also you will want to handle the case where time variable will be 0.

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

public class TimerScore : MonoBehaviour
{
    public Text text;
    public int startTime; // we will count down from this value

    private int time;

    public void StartTimer()
    {
        time = startTime;
        StartCoroutine("timer");
    }

    public void StopTimer()
    {
        StopCoroutine("timer");
        text.text = "Score: " + time;
    }

    private IEnumerator timer()
    {
        while(time > 0)
        {
            time--;
            yield return new WaitForSeconds(1f);
        }
    }
}