Drag and Drop PlayerPrefs

So I have developed drag and drop simple game that I follow from youtube “Unity UI Drag and Drop Tutorial” by BoredMormon Games. Below are my codes.

I was wondering, how to save the correct answer to playerPrefs?

Slot.cs

using UnityEngine;
using System.Collections;
using UnityEngine.EventSystems;

public class Slot : MonoBehaviour, IDropHandler {
	
	public GameObject item {
		get {
			if (transform.childCount > 0) {
				return transform.GetChild (0).gameObject;			
			}
			return null;
		}
	}

	#region IDropHandler implementation
	public void OnDrop (PointerEventData eventData)
	{
		if (!item) {
			DragHandler.itemBeingDragged.transform.SetParent (transform);
		}

		if (DragHandler.itemBeingDragged.tag == transform.tag) {
			Debug.Log ("correct");
		}
	}
	#endregion  
}

DragHandle.cs

using UnityEngine;
using System.Collections;
using UnityEngine.EventSystems;

public class DragHandler : MonoBehaviour, IBeginDragHandler, IDragHandler, IEndDragHandler {

	public static GameObject itemBeingDragged;
	Vector3 startPosition;
	Transform startParent;
	public Canvas myCanvas;

	#region IBeginDragHandler implementation

	public void OnBeginDrag (PointerEventData eventData)
	{
		itemBeingDragged = gameObject;
		startPosition = transform.position;
		startParent = transform.parent;
		GetComponent <CanvasGroup> ().blocksRaycasts= false;
	}
	#endregion
	
	#region IDragHandler implementation
	public void OnDrag (PointerEventData eventData)
	{
		transform.position = Input.mousePosition;

		Vector2 pos;
		RectTransformUtility.ScreenPointToLocalPointInRectangle(myCanvas.transform as RectTransform, Input.mousePosition, myCanvas.worldCamera, out pos);
		transform.position = myCanvas.transform.TransformPoint(pos);
	}
	#endregion

	#region IEndDragHandler implementation

	public void OnEndDrag (PointerEventData eventData)
	{
		itemBeingDragged = null;
		GetComponent <CanvasGroup> ().blocksRaycasts = true;
		if (transform.parent == startParent) {
			transform.position = startPosition;
		}
	}

	#endregion
}

PlayerPrefs has Set and Get methods. You call them when you want to save or load. This is well documented.

Maybe I’m not understanding the question?

Never mind, I think this is the correct answer. Just add a few of these lines.

slot.cs

public class Slot : MonoBehaviour, IDropHandler {
	
	public static void Save() {
		PlayerPrefs.SetInt ("NUM OF TRUE ANSWER", 1);
		PlayerPrefs.Save();	
	}
.
.
.
		if (DragHandler.itemBeingDragged.tag == transform.tag) {
			PlayerPrefs.GetInt("NUM OF TRUE ANSWER");
			Debug.Log ("correct");
			Save ();
		}	
	}
}

DragHandler.cs

public class DragHandler : MonoBehaviour, IBeginDragHandler, IDragHandler, IEndDragHandler {

	public static GameObject itemBeingDragged { get; set; }