Your PMP Exam Formula Study Guide has given me the confidence to answer all the questions that require calculations. It really helped me in understanding the principles and with your good examples I was able to memorize by heart the formulas. I always practice my "brain dump" method prior to each review session in my study room. I am really glad to obtain your very valuable Formula Study Guide. Keep up your good works and I will surely recommend your tool to all my friends who are keen to take the PMP exam.