Statement:
All badmintons are rackets.
Some rackets are rubbers.
No rubber is a string.
Conclusion:
I. Some strings are not rackets.
II. Some rubbers may not be rackets.
III. No badminton is rubber.
Some rackets are rubbers(I) + No rubber is a string(E) → Some rackets are not strings(O). Hence, conclusion I will not follow. Some rackets are rubbers(I) → conversion → Some rubbers are rackets(I) → Probable conclusion → Some rubbers may not be rackets(O). Hence, conclusion II will follow. A + I = no conclusion. Hence, conclusion III will not follow.