You have just purchased a stereo system that cost $1,000 on the
following credit plan: no down payment, an interest rate of 18% per
year (and hence 1.5% per month), and monthly payments of $50. The
monthly payment of $50 is used to pay the interest, and whatever is
left is used to pay part of the remaining debt. Hence, the first
month you pay 1.5% of $1,000 in interest. That is $15 in interest.
So, the remaining $35 is...