Answer
a.
30 years: $R=\$ 482.77$
b.
15 years: $R=\$ 608.56$
Work Step by Step
If a loan $A_{p}$ is to be repaid in $n$ regular equal payments
with interest rate $i$ per time period,
then the size $R$ of each payment is given by
$R=\displaystyle \frac{iA_{p}}{1-(1+i)^{-n}}$
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Given
$A=60,000$
monthly=12 times per year
$i=\displaystyle \frac{0.09}{12}=0.0075$.
(a) Period is 30 years, $n=360$
$R=\displaystyle \frac{60,000\cdot 0.0075}{1-1.0075^{-360}}=\$ 482.77$.
(b) Period is 15 years, $n=180$
$R=\displaystyle \frac{60,000\cdot 0.0075}{1-1.0075^{-180}}=\$ 608.56$
