সঠিক উত্তর হচ্ছে: ৩৫
ব্যাখ্যা: Let the CP of book = Tk.x\nThen, SP of book = (100+12)×x/100=112x/100\n\nNow. the printed price =Tk.y\nThen, after the discount, the SP\n= (100−10)×y/100=90y/100\n\nSince both SP are same.\nThen, 112x/100=90y/100=xy=45/56\n= 45 : 56
