Answer:
(a) 0.0001 or 0.01%
(b) 0.01 or 1%
Step-by-step explanation:
Since there are 10 possible numeric digits (from 0 to 9), and there is only one correct digit, there is a 1 in 10 change of getting each digit right.
The probability that if you forget your PIN, then you can guess the correct sequence
(a) at random:
(b) when you recall the first two digits.