Answer:
If the deposit made today earns 2.50% on the savings
FV = PV (1+r)^n
$30,000 = PV / (1 + 0.025)^5
PV = $30,000 / (1+ 0.025)^5
PV = $26,515.63
If the deposit made today earns 3.50% on the savings
FV = PV (1+r)^n
$30,000 = PV (1+0.035)^5
PV = $30,000 / (1+0.035)^5
PV = $25,259.20
So, the amount less to be deposited today to reach this goal = $26,515.63 - $25,259.20 = $1,256.43