Y is unknown.
P is known.
D is the distance between Y and P.
We don't know what D is, but do we know what fraction of Y it is.
Is this enough information to calculate Y?
Example:
Y = unknown
P = 20
D = Y-P
D/Y = 0.6
I've spent some time transforming these numbers around but to no avail. I tried searching various types of percentage inversion but I cannot find anything that would lead me to this answer, nor do I even know what this type of percentage/fraction operation is called.
Update 1:
Snap, it just dawned on me, is it:
P / ( 1-(D/Y) )
?
Update 2: See the accepted answer for a fully explained solution.
Your finding is correct. But for future references, you can always just use algebra to solve similar equations. Your starting point is $$ \frac{D}{y} = 0.6 $$ We know that $D=y-P$, so substituting that in, we get $$ \frac{y-P}{y} = 0.6 $$ From this, it's possible to solve for $y$. Multiply both sides by $y$ to get $$ y-P = 0.6y $$ Now add $P-0.6y$ on both sides to get $$ y - 0.6y = P $$ Taking the common factor, we get $$ (1-0.6)y = P $$ And finally, dividing, $$ y = \frac{P}{1-0.6} $$ I hope that all these steps are clear to you.