Question

A letter of English alphabet is chosen at random. Determine the probability that the chosen letter is a consonant. [CBSE 2015]

Answer 1

There are 26 letters of English alphabet.

Total number of outcomes = 26

Out of 26 letters, 21 are consonants and 5 are vowels.

Favourable number of outcomes = 21

∴ P(chosen letter is a consonant) = $\frac{\mathrm{Favourable}\mathrm{number}\mathrm{of}\mathrm{outcomes}}{\mathrm{Total}\mathrm{number}\mathrm{of}\mathrm{outcomes}}=\frac{21}{26}$