At 80°C, the vapour pressure of pure liquid A is 520mm of Hg and that of pure liquid B is 1000mm of Hg. If a mixture solution of A and B boils at 80°C and 1 atm pressure, the amount of A in the mixture is (1 atm = 760mm of Hg)
(a) 50mol percent
(b) 52mol percent
(c) 34mol percent
(d) 48mol percent
