how to put in a delay in void

Questions & Answers
1

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

public class ScoreBicycles : MonoBehaviour
{
public GameObject smallbicycles;
private int health;

public MenuSceneUi ui;

void Start()
{
    //ui = GetComponent<MenuSceneUi>();

    health = smallbicycles.Length;
    print(health);

}

void OnTriggerEnter(Collider col)
{

    if (col.gameObject.tag == "MYBICYCLE")
    {
        print("it's deducting score well enough");
        health = health - 1;
        smallbicycles[health].SetActive(false);

        if (health == 0)
        {
            ui.gameOverActivated();
            health = 0;
        }
    }
    
}

}

where i want to delay is

if (health == 0)
{
// here to
// ui.gameOverActivated(); //
// health = 0; //
//here //
}

2

I want to delay of 5 second before the game is over. Please help me I only have a day to submit my project.