Answer:
Juanita is saving $0.10 a pound.
Explanation:
Find the new price that the salesman offered her, by dividing the total price by the number of pounds of stones:
21.25 / 12.5
= 1.70
This means the new price is $1.70 a pound
Then, find the difference between the new price and the original:
1.80 - 1.70
= 0.10
So, Juanita is saving $0.10 a pound