In this task, you need to count the number of times the given letter appears in the given sentence.

Sentence: 'man sitting on the side of a van playing the guitar'. Find frequency of the letter 'm'
1

Sentence: 'a couple of people are sitting at a table'. Find frequency of the letter 'e'
5

Sentence: 'a number of people on a beach with kites flying above'. Find frequency of the letter 'i'

3