Chapter 3 - Solving Inequalities - 3-2 Solving Inequalities Using Addition or Subtraction - Apply What You've Learned - Page 177: c

$1$ package of $75$ empty boxes and $1$ package of $200$ empty boxes

From part (b), the number of empty boxes of popcorn that the boosters need to buy is at least $270$ boxes. Using the given table, the boosters need to buy $1$ package of $75$ empty boxes and $1$ package of $200$ empty boxes. These packages will result to a total of $275$ empty boxes, which is enough to cover the number of boxes that the boosters need.