The problem asks for the first interest payment of a loan being paid off with a monthly annuity. Given the monthly annuity is Rp250,000.00 and the first payment (principal) is Rp22,500.00, we can calculate the interest portion.

Key information:

• Monthly annuity: Rp250,000.00
• First principal payment: Rp22,500.00

Formula for the interest portion:

$\text{Interest (I)} = \text{Total Payment (A)} - \text{Principal Payment (P)}$

Substituting the values:

$I = 250,000 - 22,500 = 227,500$

Thus, the first interest payment is Rp227,500.00.

Would you like more details on annuity calculations or further clarification?

Here are 5 related questions:

1. What is the formula for calculating the total loan amount in an annuity system?
2. How does the interest change in subsequent payments of an annuity?
3. What is the effect of increasing the interest rate on the annuity payments?
4. Can annuities be used for other financial products besides loans?
5. How do we calculate the present value of an annuity?

Tip: In annuity systems, the interest portion decreases over time, while the principal portion increases with each payment.