Re: Scripts in Pakistan
As I mentioned , the script of Urdu and other languages of Pakistan have been developed from Persian and Arabic. But as you may be aware, Indian languages contain sounds (letter) which are not present in Persian or Arabic, so scripts of these languages have been amended (basis remain the same).
Arabic Alphabet contain 28 letters which forms the basis of Persian alphabet (having 4 additional letters). When we look at Sindhi script (developed from Arabic / Persian scripts), it got 52 letters.