No rule for this one
No ending or word group predicts the article of Cent. Learn it as a pair and say it out loud: der Cent.
der Cent
It's der Cent. Cent is masculine, plural die Cent.
Das kostet neunzig Cent.
That costs ninety cents.
No ending or word group predicts the article of Cent. Learn it as a pair and say it out loud: der Cent.