A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
Let's say the absent days are in B2:AF2, and the total days in B3:AF3.
Select B2:AF2.
On the Home tab of the ribbon, click Conditional Formatting > Highlight Cells Rules > Greater Than...
In the box, enter the formula =10%*B3
Select one of the predefined formats or click Custom Format...
Click OK when done.