You can sell 60 pet chias per week if they are marked as $1 each, but only 50 per week if they are marked $2 per chia. Your chia supplier is prepared to sell you 10 chias per week if they are marked $1 per chia, and 20 per week if they are marked $2 per chia. At what price should the chias be marked so that there is neither surplus nor a shortage of chias