A number in the set {50, 51, 52, 53...,999} is randomly selected . What is the probability that it is a two-digit number? Express your answer as a common fraction.
There are 50-99 of two digit numbers
THus, 1 - 50
50 numbers.
50-999 becomes 1 - 950
So we have 50/950 = 5/95 = 1/19
Is this correct?