Answer:
6
Explanation:
First you divide 12 by 3 getting 4 showing that he took 4 quizzes a week. Now you know the amount of the quizzes he takes a week. Divide the 24 by 4 you get 6 if he takes 4 quizzes a week then it must take his 6 weeks to take all 24. another way is you see that 24 is the double of twelve right? Now double the 3 weeks and and you get six.