I am a book lover and i saw a book for Pound 97.
I am short of money , so i borrowed Pound 50 from my sister and 50 from my brother = Pound 100.
I bought the book, and had Pound 3 change. I gave brother Pound 1 and my sister Pound 1 and kept the other Pound 1 for myself. Now I owe my mum Pound 49 and my brother Pound 49. 49+49 = 98 + my Pound 1 = 99.
Where is the missing Pound ?