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

Sentence: 'a small dog sits in the rear window of a car'. Find frequency of the letter 'm'
1

Sentence: 'this is an image of a woman playing tennis'. Find frequency of the letter 'f'
1

Sentence: 'a man that is riding on a surfboard in the water'. Find frequency of the letter 't'

4