If and Else operations for Table

I have created an Excel document in which I calculated the start and end coordinates for strips. The total number of strips is 23. I generated the strip data using table options in Mathcad.

Now, I want to perform the same calculation for strip start and end coordinates directly in Mathcad. Please refer to the calculation used in cell F42 in Excel. How can I replicate this equation in Mathcad?