Answer: 300 turns
Explanation: In order to explain this problem we have to consider the relationship between the voltage for the primiry and secondary and the turns for their coils.
This expression is consequence of the Faraday law because the magnetic flux is the same for both coils then the induced emf are the same for both circuits.
They are reñated as follow:
Vs=Vp*Ns/Np where Vs and Vp are the voltage for the secondary and primary coil, respectively.
Ns and Np are the turns for the secondary and primary coil, respectively.
Then we have:
Ns=Vs*Np/Vp= 16*2250/120=300