Answer:
1 /100
Step-by-step explanation:
Probability = (number of required outcomes / number of total possible outcomes)
Total possible outcomes = count of all 3 digit numbers ={100, 101,... 999} = 900
Required outcome = count of Three digit numbers with all 3 digits being the same = {111,222,333,444,555,666,777,888,999} = 9
Hence, probability that selected number has all 3 digits being the same :
9 / 900 = 1 /100