Explanation of a formual

HI All,

I am just learning formulas in excel.

I inherited a work sheet that had this formula used.

=A5/(1-(A13+B14))

in this case I know that

A5 is $10.   (round to zero decimal)

A13 is 40%

B14 is 0%

the solution is  $17    (round to zero decimal)

This is supposed to be a markup calculation but outside of excel I come up with $14.

Can anyone explain the formual and how it arrives at $17.

also what is the use or purpose of the (1-   portion of the formula.

Thank you in advance and I apologize for me basic understanding in advance