Ok I can help you on number 5 and 6. Sorry I dont understand number 7. You are correct on number six. There is not enough information because they do not say how many are 12 and how many are younger than 12. So on number 5 you would take 67 and divide it by 5. That is 13.4 so your answer for number 5 would be 13.4. Hope this helps!