Here are some equations which are important points when studying for your PMP exam.
Program Evaluation Review Technique (PERT)
This equation takes three estimates, Optimistic, Realistic, and Pessimistic, and averages them out with a weight given to Realistic.
Three point estimation just uses the average.
Standard deviation and Variance use Pessimistic and Optimistic as well.
Present Value and Future Value are financial calculations.
p=the number of periods, i=interest rate