Car payment problem

[Roll caller]

Here is the problem. The car costs $13,574.93. You make a 20% down payment. I need to know calculate a monthly payment for 36 months @ 5.34%. My question is since the interest rates is not in years what what I use for t=time. I can't remember how to input months in the equation. This is for MA 103 Foundations of Mathematics. Thanks for any assistance.