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

Sentence: 'three birds are sitting on a tree in a forest'. Find frequency of the letter 'h'
1

Sentence: 'a person is riding in a cart pulled by a horse'. Find frequency of the letter 'a'
4

Sentence: 'several crates next to each other that have vegetables in them'. Find frequency of the letter 'v'

3