If I have only 10 to 15 minutes in which I become paak and have to do ghusl and the prayer time would end within those 10 to 15 minutes, and it is not possible for a person like me to do ghusl that quickly, is that prayer fardh on me?
بِسْمِ اللهِ الرَّحْمنِ الرَّحِيْم
In the name of Allah, the Most Gracious, the Most Merciful
It depends on your haidh days. If your haidh finishes at 10 days, and there is enough time left for you to say Allahu akbar before the ending time of a salaah, then that salaah is fardh upon you (even if there doesn’t remain enough time to read the salaah). You need to read it as qadha after your ghusl.
If your haidh finishes in less than 10 days, and there is enough time left to take a bath and say Allahu Akbar before the ending time of a salaah, then that salaah is fardh upon you.
Only Allah knows best
Written by Alimah Sumeyye Sofu
Checked and approved by Mufti Mohammed Tosir Miah
Darul Ifta Birmingham
 Raddul Muhtar 1/493 Darul Kutub Ilmiyyah Beirut