Conditional Formatting Excel with formula for 2 cells

Question

I want to set a conditional format such that

Cell B minus Cell A , if number is more than 15, cell B should turn red in colour. This should be for ALL cells in column B. How do I have it such that the difference between the 2 cells affect the conditional formatting, and this is translated down the rest of the cells in that column?

Then, I want it to be the same when Cell C minus Cell B, if number is more than 15, Cell C should turn red in colour. When Cell D minus Cell C, if number is more than 15, Cell D turns red in colour... etc.

Also, what should be the cells that are selected for the formula?

Answer 1

Select the Columns B to what ever Column is your last. Go to Conditional-Formatting -> New Rule, then click on the last option (new rule with formula or what ever it's called in english). then use this Formula:

=IF(B1<>"",(B1-A1)>15,0)

Then click on the format button and from the fill tab select the red color.

Answer 2

Under the Conditional Formatting button, I was able to create a new rule with the formula =B2>A2+15, then added the appropriate formatting. I then used Format Painter to drag it to the necessary cells.