Security code .....Level pending
I bought a new Smart Phone this New Year. In this Smart Phone it has a \(4\) digits security code number. Without Security Code no one can access this phone. I want to give it a strong security code so that every digit of the code is different (like 0123, 1234, 6789 etc.) But for easily remember this security code its sum of digits must be \(8\) (like 0125, 1034 etc.) How many choices I have left?