Question

6. You charged $2,551 on a credit card. If you pay the minimum payment per month of $44, you will pay it off after making 99 payments. If you pay $10 more per month, you will pay it off 32 months sooner.  How much total interest will you save?
7. You charged $3,205 on a credit card. If you pay the minimum payment per month of $46, you will pay it off after making 297 payments. How much total interest will you pay?
8. You plan to start investing and will invest $146 per month. You will make your first deposit today. If the rate is 9.57%, how much will you have in 5 years?
9. You would like to have $34,239 in 16 years.. If the rate is 8.46%, how much do you have to invest each year?
10 You would like to have $29,020 in 15 years. If the rate is 8.08%, how much do you have to invest each month?

Answer 1

1.
=Original payments*n-New payments*n2
=44*99-(44+10)*(99-32)
=738.0000

2.
=Payments*n-Amount borrowed
=46*297-3205
=10457.0000

3.
Future value of annuity due=Amount/periodic rate*((1+periodic rate)^n-1)*(1+periodic rate)=146/(9.57%/12)*((1+9.57%/12)^(12*5)-1)*(1+9.57%/12)=11267.3899

4.
Savings=Future Amount*rate/((1+rate)^n-1)=34239*8.46%/((1+8.46%)^16-1)=1086.0873

5.
Savings=Future Amount*periodic rate/((1+periodic rate)^n-1)=29020*(8.08%/12)/((1+8.08%/12)^(15*12)-1)=83.2708