A function f from integers to integers is defined as fn=n+3,  n∈  oddn/2,   n∈  even Suppose  k∈  odd  and  fffk=27.   Then the value of k is ______

k∈odd   fk=k+3ffk=k+32if  k+32 is odd, then  27=k+32+3   or k = 45 which is not possible. Therefore,  k+32is even. Thus,27=fffk=fk+32=k+34 ∴     k=105Verifying   fff105=ff108=f54=27∴    k=105