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

Sentence: 'there is a stop sign that has a reflection in a puddle'. Find frequency of the letter 'e'
5

Sentence: 'people waiting on a train platform in a wooded area'. Find frequency of the letter 'p'
3

Sentence: 'a close up of a small car with a dog inside'. Find frequency of the letter 'a'

5