#
#  A simple loan payment calculator for a car loan
#

#
#  Read amount borrowed, annual interest rate and repayment time (in years)
#
amount_borrowed = input("How much are you going to borrow? ")
interest_rate = input("Enter the interest rate per year (5% as 0.05): ")
years = input("Enter the number of years to repay the loan: ")

#
#  Get the values entered by the user into the form expected by the
#  equation.  Repayment period needs to be in number of payments, and 
#  interest rate needs to be per payment, not per year.  As a result 
#  we need to multiply / divide by 12 for monthly payments. 
#
monthly_rate = interest_rate / 12.0
num_payments = years * 12

#
#  Compute the payment amount
#
payment_amount = (monthly_rate * amount_borrowed) / (1 - (1 + monthly_rate) ** -num_payments)

#
#  Display the result, formatting it to two decimal places
#
print "Your monthly payment will be",("%.2f" % payment_amount)
print "The total cost of borrowing was",("%.2f" % (payment_amount * num_payments - amount_borrowed))