• What is the ruling on performing voluntary prayers during official working hours?
There is no harm if there was break time during official working hours, but if not then it is impermissible. And Allah Knows Best.
• What is the amount of the Fitr Zakah(obligatory charity) of Ramadhaan?
The Fitr Zakah of Ramadhaan is a Sa`(2500 grams) from what the people of that country or state eat the most.
• Is it permissible for a woman to swear a false oath by the Holy Quran to please her distrustful husband?
It is forbidden for a person to do so since this is considered a false oath(Yamaan Ghamoos) which dips(Yaghmos) its taker in Hellfire if he/she doesn`t seek repentance, and he/she has to expiate for that oath. You should avoid any doubtful acts so that your husband`s chest remains clear from the evil suggestions of the devil.
• What is the ruling on singing and listening to it while accompanied and unaccompanied by musical instruments?
Singing and listening to it unaccompanied by musical instruments is permissible as long as it isn`t practiced as a profession and is done by a man to other men, or a woman to other women with maintaining that no temptations are involved. The words of the song should be Islamic, and if temptation was likely to happen, then the singing becomes definitely forbidden. Temptation here means: whatever leads to committing a sin. In Islamic Sharia, singing accompanied by musical instruments such as the lute and the like is forbidden, and listening to it as well. The reason behind that is the fact that the musical instrument itself is forbidden. However, striking the tambourine and singing Islamic songs are permissible in weddings, circumcisions and the like.