8 for security purposes i regularly change my six-digit passcode for internet banking. i always choose a code that is made up of three different two-digit square numbers (i.e. square numbers between 10 and 99), with the sixth digit the same as the first digit [1] (a) which two digits never appear in any of my passcodes? how many different passcodes can i use? (b) [2] the sum of the six digits of my current passcode is also a square number. (c) what is my current passcode