Question

A bank asks for a 3-character PIN code. The first character is a letter. The other two characters are digits between 0 and 9 inclusive. a How many choices are possible for each character of the code? b What is the total number of 3-character PIN codes possible? Amy chooses a PIN code beginning with the letter A. c How many different PIN codes are possible for Amy? (5 marks)

Answer 1

a) 26 choices for the first character, 10 choices for the second and 9 choices for the last character (if assuming the digits can’t be repeated. if it can be repeated then it’s 10 choices for both)

b) 26 x 10 x 9 = 2340

c) bc the first pin code is fixed (you can’t change it), there is 90 different pin codes (the digits) for Amy to try