Question: How much will be the interest of a loan of $P345,000$ that will mature after $3$ years and $9$ months with a rate of $2.5\%$ compounded quarterly? Round-off to $2$ Decimal Places
1. **State the problem:**
Calculate the interest on a loan of $345,000$ that matures after $3$ years and $9$ months with an interest rate of $2.5\%$ compounded quarterly.
2. **Formula used:**
The compound interest formula is:
$$A = P \left(1 + \frac{r}{n}\right)^{nt}$$
where:
- $A$ is the amount after interest
- $P$ is the principal amount ($345,000$)
- $r$ is the annual interest rate (as a decimal, so $0.025$)
- $n$ is the number of compounding periods per year ($4$ for quarterly)
- $t$ is the time in years
3. **Convert time to years:**
$3$ years and $9$ months = $3 + \frac{9}{12} = 3.75$ years
4. **Calculate the amount $A$:**
$$A = 345000 \left(1 + \frac{0.025}{4}\right)^{4 \times 3.75}$$
5. **Simplify inside the parentheses:**
$$1 + \frac{0.025}{4} = 1 + 0.00625 = 1.00625$$
6. **Calculate the exponent:**
$$4 \times 3.75 = 15$$
7. **Calculate $A$:**
$$A = 345000 \times (1.00625)^{15}$$
8. **Calculate $(1.00625)^{15}$:**
$$ (1.00625)^{15} \approx 1.09744 $$
9. **Calculate $A$:**
$$ A \approx 345000 \times 1.09744 = 378,016.80 $$
10. **Calculate the interest $I$:**
$$ I = A - P = 378,016.80 - 345,000 = 33,016.80 $$
**Final answer:** The interest on the loan is approximately $33,016.80$ rounded to two decimal places.