Statements: Only good singers are invited in the conference. No one without sweet voice is a good singer. Conclusions: 1 All invited singers in the conference have sweet voice. 2 Those singers who do not have sweet voice are not invited in the conf

The statement asserts that a good singer always has a sweet voice and only good singers are invited in the conference. This implies that all those invited in the conference have sweet voice and those who do not have sweet voice are not invited. So, both I and II follow.