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

Sentence: 'there is no image here to provide a caption for'. Find frequency of the letter 'o'
5

Sentence: 'a couple of people that are on a baseball field'. Find frequency of the letter 'c'
1

Sentence: 'a mand and a woman tossing frisbees into a net'. Find frequency of the letter 's'

4