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

Sentence: 'a blue train on a track next to another track'. Find frequency of the letter 'c'
2

Sentence: 'there is a woman pointing at something with her dog'. Find frequency of the letter 'i'
5

Sentence: 'a ram nurses a baby sheep in a grassy area'. Find frequency of the letter 'g'

1