Answer: their losses will be $3,500 if they don't trade the permits and $2500 if they trade them.
Explanation:
Their losses if they don't trade the permits.
Farmer A = $25 *50 = $1,250
Farmer B = $50 * 50 = $2,500
Total losses $3,750
Their losses if they trade the permits
Farmer B buys farmer A permits and pays $1,250 and loses $1,250
Farmer A has losses $1,250 because he has sold its permits and has received $1,250 but he can't applied the 100 Tons. So 50 *25 =$1,250
Total loss= $1,250 + $1,250
Total loss= $2,500