(c) As we know the, frequency of sound wave produced in a stretched wire is directly proportional to square root of tension in the wire i.e., f∝√T Let T be the initial tension. Therefore, for air column, fC∝√T⋅⋅⋅⋅⋅⋅⋅(i) According to question, first overtone i.e., 3fC∝√T+8⋅⋅⋅⋅⋅⋅⋅(ii) From Eq. (i) and Eq. (ii), we get