well 90.87 for 5 times is 90.87 * 5 = 454.35, and we know that's only the 65%, so let's say "x" is the whole price or namely the 100%.
if we know that 454.35 is 65%, what is the 100%?
[tex]\bf \begin{array}{ccll} amount&\%\\ \cline{1-2} x&100\\ 454.35&65 \end{array}\implies \cfrac{x}{454.35}=\cfrac{100}{65}\implies \cfrac{x}{454.35}=\cfrac{20}{13}\implies 13x=9087 \\\\\\ x = \cfrac{9087}{13}\implies x = 699[/tex]
