The cost of 7 pounds is 280 dollars.
Therefore the cost of per pound is by unitary method is,
Therefore, the cost per pound is 40 dollar.
It is given that the pound are decrease by 25 percent.
Therefore.,
The cost per pound reduces to ,
To calculate the cost per pound after decrease is,
The difference of original cost per pound and cost per pound after decrease.
The cost per pound after decrease is 30 dollar.