The greater number is 21, this is correct since 21 + 3 is 24, and 21 - 3 is 18. Thus, it fulfills all necessary requirements
5 * 7 = 35. App. 35 meatballs will be eaten.
12 + 12 + 12 = 36.
If he wants to have enough meatballs for everyone at the party, he needs to thaw out 3 pounds of hamburger meat.