A company sells bicycle locks with a combination made of 3 numbers. Each number can be any digit from 0 to 9 and the digits may be repeated.
One of these locks is chosen at random. What is the probability that the middle digit is 0?
There are a total of 10 possibilities for each digit in the combination (0-9), so there are a total of 10^3 = 1000 possible combinations for the lock.
Out of these 1000 combinations, there are 10 possibilities where the middle digit is 0: 001, 010, 020, 030, 040, 050, 060, 070, 080, 090.
Therefore, the probability that the middle digit is 0 is 10/1000 = 1/100 = 0.01 or 1%.