Answer:
b(20) = 3 means that for 20 boxes of cards sold, 3 badges were earned.
Explanation:
The number of badges earned based on the number of boxes of cards sold means that badges earned are a function of the number of boxes of cards sold.
b(20) means the number of badges earned for selling 20 boxes of cards.
b(20) = 3 means that for 20 boxes of cards sold, 3 badges were earned.