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

Sentence: 'a photo of a couple of people at a convention'. Find frequency of the letter 'v'
1

Sentence: 'a man in costume talking on a cell phone'. Find frequency of the letter 'm'
2

Sentence: 'a batter is preparing to hit an oncoming pitch'. Find frequency of the letter 'e'

2