A mixture of two gases A and B in the mole ratio `2:3` is kept in a 2 litre vessel. A second 3 litre vessel has the same two gases in the mole ratio `3:5`. Both gas mixtures have the same temperature and same pressure. They are allowed to intermix and the final temperature and pressure are the same as the initial values, the final volume beingh 5 litres. Given theat the molar masses are `M_(A)` and `M_(B)` . what is the mean molar mass of the final mixture `:`

Options

A. `(77M_(A)+123M_(B))/(200)`
B. `(123M_(A)+77M_(B))/(200)`
C. `(77M_(A)+123M_(B))/(250)`
D. `(123M_(A)+77M_(B))/(250)`

Answer

A