Components \( A \) and \( B \) form an azeotrope. The saturation vapor pressures of \( A \) and \( B \) at the boiling temperature of the azeotrope are 87 kPa and 72.7 kPa, respectively. The azeotrope composition is __________ mol% \( A \) (rounded off to the nearest integer).
% Given
GIVEN:
\[
\ln \left( \frac{\gamma_A}{\gamma_B} \right) = 0.9 \left( x_B^2 - x_A^2 \right)
\]
where \( x_i \) and \( \gamma_i \) are the liquid phase mole fraction and activity coefficient of component \( i \), respectively.