## Problem Design a loan management system. A loan has a principal, annual interest rate, and term in months. Payments reduce the outstanding balance. ```python class Loan: def __init__(self, principal: float, annual_rate: float, term_months: int): ... def monthly_payment(self) -> float: # fixed amortized payment def make_payment(self, amount: float, month: int) -> None: def outstanding_balance(self, after_month: int) -> float: def is_paid_off(self) -> bool: def payment_schedule(self) -> list[dict]: # [{month, payment, principal_paid, interest_paid, balance}] ``` Use the standard amortization formula: `M = P * r*(1+r)^n / ((1+r)^n - 1)` where `r = annual_rate/12`. ## Example ``` loan = Loan(10000, 0.06, 12) # $10K at 6% for 12 months loan.monthly_payment() -> ~860.66 loan.outstanding_balance(after_month=6) -> ~5136.98 ``` ## Follow-ups 1. How does an early payoff (larger payment) affect the remaining schedule? 2. Add a `LoanPortfolio` class that manages multiple loans and reports total outstanding debt. 3. How would you handle variable interest rates (rate changes per quarter)? 4. Design the database schema to store loan state and payment history.

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Loan Company - OOD Loan Lifecycle with Amortization and Repayment

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Problem Design a loan management system. A loan has a principal, annual interest rate, and term in months. Payments reduce the outstanding balance. Use the standard amortization formula: M = P r(1+r)^n / ((1+r)^n - 1) where r = annual_rate/12. Example Follow-ups How does an early payoff (larger payment) affect the remaining schedule? Add a LoanPortfolio class that manages multiple loans and reports total outstanding debt. How would you handle variable interest rates (rate changes per quarter)? D…

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Loan Company - OOD Loan Lifecycle with Amortization and Repayment

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