I thought 'un' (masculine/neuter) goes with 'doi', and 'o' (feminine) with 'două'? Now I'm confused....
EDIT: I found the answer somewhere else in a discussion:
Quoting relox84: Fruct is actually neither masculine nor feminine: it's a neuter noun.
In Romanian, neuter nouns behave like masculine nouns in the singular and feminine nouns in the plural. They are recognisable by their ending in the plural, which is typically -e or -uri, whereas masculine nouns have a plural in -i.
Masculine noun: un câine - doi câini
Neuter noun: un fruct - două fructe
Feminine noun: o fată - două fete