Answer:
The maximum amount saved will be 13.4 dollars
Explanation:
To get the maximum saved, the calls should be for 3 minutes or less.
Without fees: (assuming calls for 3 minutes or less)
1 hours = 60 minutes
60 minutes x 1.60 per minute = 96
Total                       96
With the fee to receive a discount:
charged to Country A x discount
       96         x   40%    = 38.4 discount
gross - discount = net
  96  -  38.4   = 57.6 net
+ monthly fee    25
total            82.6
Amount saved 96 - 82.6 = 13.4