Two sitar strings, A and B playing the note ' Dha ' are slightly...

Two sitar strings, $A$ and $B$ playing the note '$Dha$' are slightly out of tune and produce beats of frequency $5Hz$. The tension of the string $B$ is slightly increased and the beat frequency is found to decrease by $3Hz$. If the frequency of $A$ is $425Hz$. The original frequency of $B$ is