Camille harris has a checking account with the bank of the northwest. she earns 0.5% per month. if she maintains a balance of $1200, her checks are free, but if she goes under that amount, each check will have a two cent charge on it. for balances under $600, there is a service fee of $4 per month. use the equation i = rb - sx - f to determine her earnings on the account if she has a balance of $1500 and she writes 25 checks.
a.$3.00
b.$3.50
c.$7.00
d.$7.50