[填空题]
The first two characters of a student ID xiaa5 svq2qy c( a:q5drw).xb4 (.yum number is composed md :ii/ z5fmo.h zs0m9by the following rules:o/zm fd. ih59mmiz:s0 - one letter is chosen from student's first name at random;
- one digit is chosen from student's date of birth at random (dd/mm/yyyy).
Bob Stewart was born on the 12th of January, 2001(12/01/2001). Find the probability that
1. Bob's ID starts with "B1".
2. Bob's ID starts with "B" or its second character is "2".
3. Bob's ID starts with "O" given that the second character is not 0 . ≈