An ideal solution is prepared from A and B (both are volatile). The composition of the solution is such that the total vapour pressure is harmonic mean of vapour pressures of pure `A(P_(A)^(@))` and pure `B(P_(B)^(@)).[P_(A)^(@) ne P_(B)^(@)]`
If `x_(A), x_(B)` represents mole freaction of A and B in solution respectively and `y_(A) ` and `Y_(B)` represents mole fraction of A and b in vapour phase, then answer the following questions.
The value of `x_(A)` is :

Options

A. `1-y_(A)`
B. `1-y_(B)`
C. `(P_(A)^(@))/(P_(A)^(@) + P_(B)^(@))`
D. `(P_(B)^(@))/(P_(A)^(@) + P_(B)^(@))`

Answer

D