Always 0/10 Quiz.py - mistake

import datetime
import random

from questions import Add, Multiply



class Quiz:
    questions = []
    answers = []

    def __init__(self):
        questions_type = (Add, Multiply)
        # generate ten random questions with numbers from 1 to 10
        for _ in range(10):
            num1 = random.randint(1,10)
            num2 = random.randint(1,10)
            question = random.choice(questions_type)(num1,num2)
            self.questions.append(question)
            # add these questions into self.questions

    def take_quiz(self):

        # log the start time
        self.start_time = datetime.datetime.now()
        # ask all of the questions
        for question in self.questions:
            # log if they got the question right
            self.answers.append(self.ask(question))
        else:
            # log the end time
            self.endtime = datetime.datetime.now()
            # show a summary
        return self.summary()

    def ask(self, questions):
        correct = False
        # log the start time
        question_start = datetime.datetime.now()
        # capture the answer
        answer=input(questions.text + " = ")
        # check the answer
        if answer == str(questions.answer):
            correct == True
        # log the end time
        question_end = datetime.datetime.now()

        # if the answer is right, send back True
        # else, send back False
        # send back the elapsed time too
        return correct, question_end - question_start

    def total_correct(self):
        # return the total number of correct answers
        total = 0
        for answer in self.answers:
            if answer[0]: # True/False
                total+=1
        return total



    def summary(self):
        # print how many you got right and the total of questions like 8/10
        print("Yoi got {} out of {} right.".format(
            self.total_correct(), len(self.questions)
        ))
        # print total time for the quiz
        print("It took you {} seconds total.".format(
            (self.endtime-self.start_time).seconds
        ))

Quiz().take_quiz()