At \( 363 \, \text{K} \), the vapour pressure of A is \( 21 \, \text{kPa} \) and that of B is \( 18 \, \text{kPa} \). One mole of A and \( 2 \) moles of B are mixed. Assuming that this solution is ideal, the vapour pressure of the mixture is _______ \( \text{kPa} \). (Round off to the Nearest Integer).
