If someone bought a car from an interest-based bank and then sold it to another person, does the second person bear any sin if they use the car's price to pay the installments owed to the bank?
When the buyer purchased the car, it became their property, and the price became their responsibility. The bank acts as the seller's agent for receiving the payment. Therefore, there is no sin on the second buyer, God willing, as long as the bank does not impose an increase in the amount if a payment is delayed. And Allah The Almighty Knows Best.
Is hair extension permissible?
All Perfect Praise is due to Allah, The Lord of The Worlds
It is impermissible for the man and the woman to apply a human`s hair as extension, but using artificial hair is permissible for the married woman after obtaining the approval of her husband so long as non-Mahrams don`t see her. And Allah Knows Best.
Is it permissible for a woman to ride a taxi without a Mahram (unmarriageable kin) in order to attend a gathering of knowledge?
It is permissible for the woman to pursue the knowledge that she needs in order to perform the religious requirements due on her if there was nobody to teach her at home, provided that there is no temptation involved. Moreover, we don`t recommend that she rides a taxi without a Mahram although such an act isn`t from the forbidden Khulwah (seclusion).
Can the Christian widow whose married from a Muslim become an heir of his?
All perfect praise be to Allah the Lord of the Worlds. May His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
A Christian widow can`t inherit her Muslim husband because their religions are different. And Allah The Almighty Knows Best.