The Rule of 72 is an easy way to calculate how long it will take for your investment to
double at a given interest rate if you don't make any further deposits.
The premiums are flexible and are designed to cover the costs of the insurance with the difference being applied to a cash value that
grows at a given interest rate.
Tightenings and easings in monetary policy showed up largely through credit rationing — the ease or difficulty in obtaining a
loan at a given interest rate.
Credit cards are fairly standard in that you're able to purchase a product or service with loaned money
at a given interest rate for a set period of time.
With a preapproval, on the other hand, you complete a full application, the lender pulls your credit report and score and puts an offer in writing to give you a
loan at a given interest rate.
At a given interest rate, each dollar you knock off the loan will save the same amount of interest.
Within all the loans
at a given interest rate, I would apply extra payments to the smallest loans first for the psychological boost and decrease in minimum payment mentioned in Pete's answer, but this is clearly a personal (and relatively unimportant) decision.
This equation is essential if you are calculating how much money you'll need in the future because of inflation, or what the amount would be if you choose to invest the money
at a given interest rate.
@Ali Loan constant is the payment amount for a loan of $ 1
at a given interest rate and term.