"I have two rooms and a bedroom."

Translation: У мене є дві кімнати і спальня.

[UteEff]

Could "у мене є дві кімнати і одна спальня" also be correct?

[GeneM.]

Я маю дві кімнати і спальню. But кімнати is feminine, so wouldn't the ending change here? (accusative plural)

[skstudio]

кімнати is the accusative plural. It is also the nominative plural and genitive singular.

[bright_flash]

Should be pronounced мЕне, not менЕ because it is preceded by a preposition

[deactivated user]

I don't understand why 'спальню' and 'спальня' are good answer. I can use either nominative or accusative case here ?

[deactivated user]

This depends on the construction you use. If you use the verb «мати» 'to have', then you need an accusative: Я ма́ю дві кімна́ти і спа́льню (this construction is basically the same as the one English uses). If you use the existence construction, «У ме́не є дві кімна́ти і спа́льня» (literally, 'at my [possession, there] are two rooms and [a] bedroom'). Both are equally natural, and you can use either.

You can't use nominative if you use the verb "to have" («Я ма́ю дві кімна́ти і спа́льня» is wrong), and you can't use accusative if you have the "there is" construction («У ме́не є дві кімна́ти і спа́льню» is wrong). If Duolingo suggests one of these, it's a bug.

[Natalka_Polyak]

"У мене є дві кімнати і спальня кімната". Чому так не може бути?

[Tielbert]

Because спальня is noun, not adjective. You can say спальнА кімната.