1) Are men and women allowed to pray together during Hajj season? I thought that Men and Women are allowed to perform Tawaf around the Kaba together? 2) Is it true that men cannot pray behind a woman.

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

The rows of men should not mix with those of women during prayer nor should there be women or men praying in the same row. In fact, the normal and correct situation is that men should be in the first rows and women behind them. It is narrated in a sound Hadeeth that the Prophet said: “The best rows for men are the first ones and the worst rows for them are the last ones. The best rows for women are the last rows and the worst rows for them are the first ones.”

But if there is no choice and it is unavoidable that men get mixed with women in the same rows like during Hajj, for instance, then this is excused as it is beyond the person's willpower and Allah Says (what means): {Allah burdens not a person beyond his scope.} [Quran 2:286]

Allah also Says (what means): {So fear Allah as much as you are able and listen and obey…} [Quran 64:16]

Besides, the Prophet said: “Allah has forgiven for my Ummah what they do by mistake, what they do out of forgetfulness, and what they are forced to do.” [Ibn Maajah and Al Haakim who said that it is a sound Hadeeth]

But remember that the person should take all his precautions to avoid getting mixed with people of the opposite sex.

Allah knows best.