Answer:
1/67600
Explanation:
Possible digits: {0,1,2,3,4,5,6,7,8,9}
Number of possible Personal Identification Number (PIN) is:
Number of possible letters*Number of possibles letters*Number of possible digits*Number of possible digits = 26*26*10*10 = 67600
The probability of a thief guessing the correct pin on the first try is: 1/67600