Date Calculation

edited 12/09/19 in Smartsheet Basics

I have 3 columns. 1 column is the date that the time begins, the 2nd is a factor that is either 1.5, 3 or 5. It is always one of these three numbers. The 3rd column is for the end date that is auto-calculated by taking the date in column 1 and multiplying it be the factor selected in column 2. How do I do that? I am really racking my brain about this.

Thank you.