Answer:
21,615.26 interest saved.
Explanation:
The interest saved will be the interest that the extra payment could have generated in the remainder of the loan:
[tex]PV \div \frac{1-(1+r)^{-time} }{rate} = C\\[/tex]
PV $22,000.00
time 342 (360 payment - 18 months)
rate 0.004583333 (5.5% / 12 )
[tex]22000 \div \frac{1-(1+0.00458333333333333)^{-342} }{0.00458333333333333} = C\\[/tex]
C $ 127.526
To know the interest we multiply the cuota by the loan life and then, subtract the principal:
127.53 x 342 - 22,000 = 21615.26