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

Sentence: 'surfboard being displayed in stor window with clothes behind it'. Find frequency of the letter 't'
4

Sentence: 'a person standing operating a cell phone in a room'. Find frequency of the letter 'n'
6

Sentence: 'a painting of a black individual with a red umbrella on a concrete wall'. Find frequency of the letter 'o'

3