Hi Pradeep,

Below is the code:

Schedule job code:

global without sharing class ScheduleAccountDeletion implements Schedulable {
    public void execute (SchedulableContext sc){
       AccountCount.ExtraAccountDeletion(); 
    }

}

helper class for account deletion:

public class AccountCount {
    public static void ExtraAccountDeletion(){
        List<Account> accList = [Select Id from Account where createdDate >=Today order by CreatedDate asc];
        List<Account> accListDeletion = new list <Account>();
        if(accList.size()>10){
            for(integer i=10; i<accList.size();i++){
                accListDeletion.add(accList[i]);
            }
        }
        
        if(accListDeletion.size()>0){
            try{
                Database.Delete(accListDeletion);
            }catch(exception e){
                System.debug('Exception: '+e );
            }
        }
    }

}

Code for scheduling the jobs first time

ScheduleAccountDeletion accDeletion = new ScheduleAccountDeletion();
System.schedule('Extra Account Deletion: at 00 mins', '0 0 * * * ?', accDeletion);
System.schedule('Extra Account Deletion: at 15 mins', '0 15 * * * ?', accDeletion);
System.schedule('Extra Account Deletion: at 30 mins', '0 30 * * * ?', accDeletion);
System.schedule('Extra Account Deletion: at 45 mins', '0 45 * * * ?', accDeletion);

Please let me know if it answers your query.