The vapour pressure of a pure liquid A is 80 mmHg at 300K.It forms an ideal solution with liquid B.When the mole fraction of B is 0.4,the total pressure was found to be 88 mmHg.The vapour pressure of liquid A would be

Question

$\begin{array}{1 1}\text{84 mmHg}\\\text{90 mmHg}\\\text{100 mmHg}\\\text{120 mmHg}\end{array} $