Store A
Bananas cost 59 cents per pound
Store B
Bananas cost 55 cents per pound
If a customer wants to buy 10 pounds of bananas, it will cost him:
0.59 * 10 = $5.90 at Store A
and
0.55 * 10 = $5.50 at Store B
Thus,
the customer is going to save $ 5.90 - $ 5.50 = $0.40 for buying 10 pounds of bananas from Store B, rather than buying from Store A.