Logs for business vs personal

Why does TT ask you these two questions for vehicle expense?

 

Did you keep a log for business use?

yes

no

 

Did you keep a log for personal use?

yes

no

 

The next screen asks you to list the total miles driven for the year and how much was driven for business?  Regardless on how you answer the above two questions for the standard mileage deduction, you can infer what the mileage is.  Let’s say total driven is 10,000 miles and 6,000 was for business use.  Then you can calculate that 10,000 - 6,000 = 4,000 was for personal use.  Follow my logic?  

So the two questions don’t really matter since they ask for mileage anyways.