C20 · Complete neutral exit
For a fictional community display, need exactly 36 items. Pretend A packs 6 for $12; B packs 9 for $18. One $7 fee, budget $80. Whole packs/no extras. Choose lower cost among valid plans; if tied choose fewer packs. Send a useful note.
Use your own model, number sentence/strategy, check and useful message. Record actual support.