What is the ruling concerning the prayers I performed and the fasting I observed, given my previous ignorance of the obligation of ghusl (ritual bathing) after janabah (state of ritual impurity requiring ghusl) and my not washing my hair at that time? Do I have to make up for them, or is there an expiation for them, especially since I do not know their number?

According to the majority of scholars, prayers performed without proper purification must be redone. This is the more cautious approach and clears one's conscience, while some scholars hold the view that the ignorant person is not obligated to make up the prayers. As for fasting, it is valid, because ghusl (ritual bath) from janabah (state of ritual impurity) is not a condition for its validity.