The word(s) "تَجْهَلُونَ" appears in 4 verse(s) in Quran.

(1) وَجَاوَزْنَا بِبَنِي إِسْرَائِيلَ الْبَحْرَ فَأَتَوْا عَلَىٰ قَوْمٍ يَعْكُفُونَ عَلَىٰ أَصْنَامٍ لَّهُمْ ۚ قَالُوا يَا مُوسَى اجْعَل لَّنَا إِلَـٰهًا كَمَا لَهُمْ آلِهَةٌ ۚ قَالَ إِنَّكُمْ قَوْمٌ تَجْهَلُونَ

(سورة الأعراف, Al-A'raaf, Chapter #7, Verse #138)
(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) وَيَا قَوْمِ لَا أَسْأَلُكُمْ عَلَيْهِ مَالًا ۖ إِنْ أَجْرِيَ إِلَّا عَلَى اللَّهِ ۚ وَمَا أَنَا بِطَارِدِ الَّذِينَ آمَنُوا ۚ إِنَّهُم مُّلَاقُو رَبِّهِمْ وَلَـٰكِنِّي أَرَاكُمْ قَوْمًا تَجْهَلُونَ

(سورة هود, Hud, Chapter #11, Verse #29)
(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)

(3) أَئِنَّكُمْ لَتَأْتُونَ الرِّجَالَ شَهْوَةً مِّن دُونِ النِّسَاءِ ۚ بَلْ أَنتُمْ قَوْمٌ تَجْهَلُونَ

(سورة النمل, An-Naml, Chapter #27, Verse #55)
(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)

(4) قَالَ إِنَّمَا الْعِلْمُ عِندَ اللَّهِ وَأُبَلِّغُكُم مَّا أُرْسِلْتُ بِهِ وَلَـٰكِنِّي أَرَاكُمْ قَوْمًا تَجْهَلُونَ

(سورة الأحقاف, Al-Ahqaf, Chapter #46, Verse #23)
(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)