The word(s) "fifty" appears 2 time(s) in 2 verse(s) in Quran in Muhammad Pickthal translation.

(1) And verily we sent Noah (as Our messenger) unto his folk, and he continued with them for a thousand years save fifty years; and the flood engulfed them, for they were wrong-doers.

(سورة العنكبوت, Al-Ankaboot, Chapter #29, Verse #14)
(Arabic, Transliteration, Urdu (Ahmed Ali), Urdu (Jalandhry), Farsi, Yusuf Ali, Shakir, Picthal, Mohsin Khan, French, Spanish, Indonesian, Malay, German, Bosnian, Russian, Dutch, Italian, Portuguese, Tafsir - Jalal ad-Din, Tafsir - King Fahad Quran Complex)

(2) (Whereby) the angels and the Spirit ascend unto Him in a Day whereof the span is fifty thousand years.

(سورة المعارج, Al-Ma'aarij, Chapter #70, Verse #4)
(Arabic, Transliteration, Urdu (Ahmed Ali), Urdu (Jalandhry), Farsi, Yusuf Ali, Shakir, Picthal, Mohsin Khan, French, Spanish, Indonesian, Malay, German, Bosnian, Russian, Dutch, Italian, Portuguese, Tafsir - Jalal ad-Din, Tafsir - King Fahad Quran Complex)