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

Sentence: 'two boys are doing skateboard jumps in the street'. Find frequency of the letter 's'
4

Sentence: 'an elephant with broken tusks stands in front of a hill and boulders'. Find frequency of the letter 'n'
7

Sentence: 'two women in maroon shirts standing in a park holding a frisbee'. Find frequency of the letter 's'

4