In a guitar, two strings A and B made of same material are slightly out of tune and produce beats of frequency 6 Hz. When tension in B is slightly decreased, the beat frequency increases to 7 Hz. If the frequency of A is 530 Hz, the original frequency of B will be :
(1) 537 Hz
(2) 523 Hz
(3) 524 Hz
(4) 536 Hz
(1) 537 Hz
(2) 523 Hz
(3) 524 Hz
(4) 536 Hz