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

Sentence: 'cars parked outside if a retail store'. Find frequency of the letter 'd'
2

Sentence: 'the skateboarder is jumping over a huge statue of a shoe'. Find frequency of the letter 'i'
2

Sentence: 'a white cat sits on a cat tree while a black cat sits on a chair and both cats look out of a window'. Find frequency of the letter 'c'

6