Its not cheating sis Alwrdah, as its permitted to search the answers and share here
1.To which of the sahabas {companions of Prophet}, was the third daughter of our Prophet Umm Kulthum RA was married to?
Umm Kulthum RA was married to Osman Ghani RA. After the death of Rookaiya RA, Osman Ghani was appraoched by Umar RA, whose daughter Hafsa RA was now a widow. But Osman Ghani did not reply him as Abu Bakr RA. Umar Ra was bit disappointed as he recieved no such positive reply from the. Prophet saws told him that Hafsa shall get better person than Osman Ghani RA and Osman Ghani RA would get a better person than Hafsa. Initially Hafsa RA was married to our Prophet SAWS and Osman Ghani was married to Umm Kulthum RA.
2. What does Qur'an say of Qaroon?
Verse 76.of surah Qasas says "Verily, Qarun was of Musa's people, but he behaved arrogantly towards them. And We gave him of the treasures, that of which the keys would have been a burden to a body of strong men. Remember when his people said to him: "Do not exult. Verily, Allah likes not those who exult.''
(78. He said: "This has been given to me only because of the knowledge I possess.'' Did he not know that Allah had destroyed before him generations, men who were stronger than him in might
and greater in the amount they had collected But the criminals will not be questioned of their sins
79. So, he went forth before his people in his finery. Those who were desirous of the life of the world, said: "Ah, would that we had the
like of what Qarun has been given! Verily, he is the owner of a great fortune.'
80. But those who had been given knowledge said: "Woe to you! The reward of Allah is better for those who believe and do righteous deeds, and this none shall attain except the patient.''
These are the verses which deal with Qarun in chapter qasas. What we need to learn out of this is we shud n't exult of anything we
possess. We shudn't feel envious of those wealthy, as its all temporary. The real wealth is that which we possess in the world hereafter and its FOREVER. And the third is we shud be with patience and do righteous deeds apart from believing in Allah inorder to get a better reward.
3. Which was the last battle participated by Prophet SAWS?
Its Battle of Tabook. Alwardah's comment for the this answer confused me to comfirm again. And its battle of Tabook which lasted in 9th year of Hijrah. Though there was no war as the opponents did not turn up and few fled away. But it was a severe test for the believers. Its discussed in the tafseer of surah Taubah.