Hi! The total cost of this circus trip for the family would be 41 or $41.
Explanation:
If you add 7+3 to get the total amount 1 ticket for 1 adult would be, it would be 10. So 10+10 for both adult tickets would be $20. 3 child tickets would cost $21 (7x3 or 7+7+7). Last, you would add up 20+21 and would get 41 and just add the dollar sign in front.
Hope this helps! Have a good day!