Exercise 05-13:
Write a program that asks for the initial amount of debt and the monthly interest. Also, ask for the monthly amount that will be paid. Print the number of months it will take for the debt to be repaid, the full amount that will be paid, and the total interest that will be paid.
Answer:
##############################################################################
# Python From Scratch
# Author: Nilo Ney Coutinho Menezes
# Editora Novatec (c) 2010-2025 - LogiKraft 2025
# Site: https://pythonfromscratch.com
# ISBN: 978-85-7522-949-1 (Paperback), 978-85-7522-950-7 (hardcover), 978-85-7522-951-4 (ebook)
#
# File: chapter 05/exercise-05-13.py.py
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debt = float(input("Debt: "))
rate = float(input("Interest (Ex.: 3 for 3%): "))
payment = float(input("Monthly payment: "))
month = 1
if debt * (rate / 100) > payment:
print(
"Your debt will never be paid off, as the interest is higher than the monthly payment."
)
else:
balance = debt
interest_paid = 0
while balance > payment:
interest = balance * rate / 100
balance = balance + interest - payment
interest_paid = interest_paid + interest
print(f"Debt balance in month {month} is R${balance:6.2f}.")
month = month + 1
print(f"To pay off a debt of R${debt:8.2f}, at {rate:5.2f}% interest,")
print(
f"you will need {month - 1} months, paying a total of R${interest_paid:8.2f} in interest."
)
print(
f"In the last month, you would have a remaining balance of R${balance:8.2f} to pay."
)