A letter is chosen at random from all the letters of the English alphabets. The probability that the letter chosen is a vowel, is :

1. $\dfrac{4}{26}$

2. $\dfrac{5}{26}$

3. $\dfrac{21}{26}$

4. $\dfrac{5}{24}$

All the letters of English alphabets have 5 vowels (a, e, i, o and u) and total number of English alphabets = 26.

Probability that letter chosen is a vowel = $\dfrac{\text{No. of vowels}}{\text{No. of alphabets}} = \dfrac{5}{26}$.

Hence, Option 2 is the correct option.