During the transition of electron from state A to state C of a Bohr atom, the wavelength of emitted radiation is 2000 and it becomes 6000 when the electron jumps from state B to state C. Then the wavelength of the radiation emitted during the transition of electrons from state A to state B is [2025]
(1)

For A to C : ... (i)
and for B to C : ... (ii)
Now for A to B :