if the sentences had ended with ね i would have been far more easier.
btw. my examples where made for the case when some questions are asked in negative.
バナナがありませんか。
いえ。あります
はい。ありません。
well. in my language this sounds a bit weird. we normally say
バナナがありませんか。
いえ。ありません。
はい。あります。
but that is another story.
dunno why but i had problems remembering this.