EXPLANATION
Let's see the facts:
Number of years: 5
Account period = 2 times/month
Nonbank ATM -------> once/ month
If he switch the account to Old River Bank he would save:
$6 - $4.95 = $1.05
Transaction cost_Trust Bank = $1/transaction * 2 = $2
Nonbank_Trust Bank = $2/transaction = $2
Trust Bank Cost = 2 + 2 + 6 = $10
The account in the Old River Bank would be:
Account Services = $4.95
Bank ATM Cost = $0.00
Nonbank ATM Cost = $2.5/transactions * 1 = $2.5
----------------------
$7.45
The total cost at Old River would be = $7.45
The difference between Truth Bank and Old River would be $10-$7.45 = $2.55
Gavin would save $2.55 per month.