Question

A single letter is selected at random from the word 'PROBABILITY'. What is the probability that it is a vowel?

Answer 1

There are 11 letters in the word 'PROBABILITY'.
i.e. n(S) = 11
There are 4 vowels (O, A, I, I) in the given word.
i.e. n(vowel) = 4
∴ Probability (vowel) = \[\frac{4}{11}\]